Eddington luminosity

The Eddington luminosity, also referred to as the Eddington limit, is the maximum luminosity a body (such as a star) can achieve when there is balance between the force of radiation acting outward and the gravitational force acting inward. The state of balance is called hydrostatic equilibrium. When a star exceeds the Eddington luminosity, it will initiate a very intense radiation-driven stellar wind from its outer layers. Since most massive stars have luminosities far below the Eddington luminosity, their winds are mostly driven by the less intense line absorption. The Eddington limit is invoked to explain the observed luminosity of accreting black holes such as quasars.
Originally, Sir Arthur Eddington took only the electron scattering into account when calculating this limit, something that now is called the classical Eddington limit. Nowadays, the modified Eddington limit also counts on other radiation processes such as bound-free and free-free radiation (see Bremsstrahlung) interaction.
Derivation.
The limit is obtained by setting the outward radiation pressure equal to the inward gravitational force. Both forces decrease by inverse square laws, so once equality is reached, the hydrodynamic flow is the same throughout the star.
From Euler's equation in hydrostatic equilibrium, the mean acceleration is zero,
where formula_2 is the velocity, formula_3 is the pressure, formula_4 is the density, and formula_5 is the gravitational potential. If the pressure is dominated by radiation pressure associated with a radiation flux formula_6,
Here formula_8 is the opacity of the stellar material which is defined as the fraction of radiation energy flux absorbed by the medium per unit density and unit length. For ionized hydrogen formula_9, where formula_10 is the Thomson scattering cross-section for the electron and formula_11 is the mass of a proton. Note that formula_12 is defined as the energy flux over a surface, which can be expressed with the momentum flux using formula_13 for radiation. Therefore, the rate of momentum transfer from the radiation to the gaseous medium per unit density is formula_14, which explains the right hand side of the above equation.
The luminosity of a source bounded by a surface formula_15 may be expressed with these relations as
Now assuming that the opacity is a constant, it can be brought outside of the integral. Using Gauss's theorem and Poisson's equation gives
where formula_18 is the mass of the central object. This is called the Eddington Luminosity. For pure ionized hydrogen
where formula_18☉ is the mass of the Sun and formula_21☉ is the luminosity of the Sun.
The maximum luminosity of a source in hydrostatic equilibrium is the Eddington luminosity. If the luminosity exceeds the Eddington limit, then the radiation pressure drives an outflow.
The mass of the proton appears because, in the typical environment for the outer layers of a star, the radiation pressure acts on electrons, which are driven away from the center. Because protons are negligibly pressured by the analog of Thomson scattering, due to their larger mass, the result is to create a slight charge separation and therefore a radially directed electric field, acting to lift the positive charges, which are typically free protons under the conditions in stellar atmospheres. When the outward electric field is sufficient to levitate the protons against gravity, both electrons and protons are expelled together.
Different limits for different materials.
The derivation above for the outward light pressure assumes a hydrogen plasma. In other circumstances the pressure balance can be different from what it is for hydrogen.
In an evolved star with a pure helium atmosphere, the electric field would have to lift a helium nucleus (an alpha particle), with nearly 4 times the mass of a proton, while the radiation pressure would act on 2 free electrons. Thus twice the usual Eddington luminosity would be needed to drive off an atmosphere of pure helium.
At very high temperatures, as in the environment of a black hole or neutron star, high energy photon interactions with nuclei or even with other photons, can create an electron-positron plasma. In that situation the combined mass of the positive-negative charge carrier pair is approximately 918 times smaller (the proton to electron mass ratio), while the radiation pressure on the positrons doubles the effective upward force per unit mass, so the limiting luminosity needed is reduced by a factor of ≈918×2.
The exact value of the Eddington luminosity depends on the chemical composition of the gas layer and the spectral energy distribution of the emission. A gas with cosmological abundances of hydrogen and helium is much more transparent than gas with solar abundance ratios. Atomic line transitions can greatly increase the effects of radiation pressure, and line driven winds exist in some bright stars (e.g., Wolf-Rayet and O stars).
Super-Eddington luminosities.
The role of the Eddington limit in today's research lies in explaining the very high mass loss rates seen in for example the series of outbursts of η Carinae in 1840–1860. The regular, line driven stellar winds can only stand for a mass loss rate of around 10−4–10−3 solar masses per year, whereas mass loss rates of up to 0.5 solar masses per year are needed to understand the η Carinae outbursts. This can be done with the help of the super-Eddington broad spectrum radiation driven winds.
Gamma-ray bursts, novae and supernovae are examples of systems exceeding their Eddington luminosity by a large factor for very short times, resulting in short and highly intensive mass loss rates. Some X-ray binaries and active galaxies are able to maintain luminosities close to the Eddington limit for very long times. For accretion-powered sources such as accreting neutron stars or cataclysmic variables (accreting white dwarfs), the limit may act to reduce or cut off the accretion flow, imposing an Eddington limit on accretion corresponding to that on luminosity. Super-Eddington accretion onto stellar-mass black holes is one possible model for ultraluminous X-ray sources (ULXs).
For accreting black holes, not all the energy released by accretion has to appear as outgoing luminosity, since energy can be lost through the event horizon, down the hole. Such sources effectively may not conserve energy. Then the accretion efficiency, or the fraction of energy actually radiated of that theoretically available from the gravitational energy release of accreting material, enters in an essential way.
Other factors.
The Eddington limit is not a strict limit on the luminosity of a stellar object. The limit does not consider several potentially important factors, and super-Eddington objects have been observed that do not seem to have the predicted high mass-loss rate. Other factors that might affect the maximum luminosity of a star include:
Humphreys–Davidson limit.
Observations of massive stars show a clear upper limit to their luminosity, termed the Humphreys–Davidson limit after the researchers who first wrote about it. Only highly unstable objects are found, temporarily, at higher luminosities. Efforts to reconcile this with the theoretical Eddington limit have been largely unsuccessful.


Ford Observatory

The Clinton B. Ford Observatory (Wrightwood) (Observatory Code 674) is an astronomical observatory that is associated historically with the American Association of Variable Star Observers (AAVSO). The observatory is located near the border of the Angeles National Forest and the San Bernardino National Forest near Wrightwood, California (United States). It was founded by the late astronomer Clinton B. Ford.
In 2012, the Clinton B. Ford Observatory was donated to the Los Angeles Astronomical Society (LAAS).
Telescope.
The observatory contains an 18-inch, f/7 newtonian reflector.


OPERA experiment

The Oscillation Project with Emulsion-tRacking Apparatus (OPERA) was an instrument used in a scientific experiment for detecting tau neutrinos from muon neutrino oscillations. The experiment is a collaboration between CERN in Geneva, Switzerland, and the Laboratori Nazionali del Gran Sasso (LNGS) in Gran Sasso, Italy and uses the CERN Neutrinos to Gran Sasso (CNGS) neutrino beam.
The process started with protons from the Super Proton Synchrotron (SPS) at CERN being fired in pulses at a carbon target to produce pions and kaons. These particles decay to produce muons and neutrinos.
The beam from CERN was stopped on 3 December 2012, ending data taking, but the analysis of the collected data has continued.
Detector.
OPERA, in Hall C of the Gran Sasso underground labs, was built in 2003–2008. The taus resulting from the interaction of tau neutrinos are observed in "bricks" of photographic films (nuclear emulsion) interleaved with lead sheets. Each brick weighs 8.3kg; the two OPERA supermodules contain 150,000 bricks arranged into parallel walls interleaved with plastic scintillator counters. Each supermodule is followed by a magnetic spectrometer for momentum and charge identification of penetrating particles. During data collection, a neutrino interaction and its corresponding brick are tagged in real time by the scintillators and spectrometers. These bricks are extracted from the walls asynchronously with respect to the beam for film development, scanning and for the topological and kinematic search of tau decays.
Tau neutrinos.
In total, five tau neutrinos were detected. On 31 May 2010, OPERA researchers observed the first tau neutrino candidate event in a muon neutrino beam. On 6 June 2012, OPERA announced the observation of a second tau neutrino event. On 26 March 2013, the experiment caught for the third time a muon neutrino oscillating into a tau neutrino during travel from CERN to LNGS. The fourth one was found in 2014, and the fifth was seen in 2015.
Time-of-flight measurements.
In September 2011, OPERA researchers observed muon neutrinos apparently traveling faster than the speed of light. In February and March 2012, OPERA researchers blamed this result on a loose fibre optic cable connecting a GPS receiver to an electronic card in a computer. On 16 March 2012, a report announced that an independent experiment in the same laboratory, also using the CNGS neutrino beam, but this time the ICARUS detector, found no discernible difference between the speed of a neutrino and the speed of light. In May 2012, the Gran Sasso experiments BOREXINO, ICARUS, LVD and OPERA all measured neutrino velocity with a short-pulsed beam, and obtained agreement with the speed of light, showing that the original OPERA result was mistaken. Finally in July 2012, the OPERA collaboration updated their results. After the instrumental effects mentioned above were taken into account, it was shown that the speed of neutrinos is consistent with the speed of light. This was confirmed by a new, improved set of measurements in May 2013.


Layue

Làyuè is the last month of the year in the Chinese calendar. In general, the Great Cold is in "Làyuè". The name comes from the winter sacrifice, just as February. In Japan, the month is not called Layue but Shiwasu (literally 'priests' busiest month')
Events.
Aisin-Gioro Puyi, 12th Qing Emperor of China, issued the imperial abdication edict at "Làyuè 25th 1911"


Maurice Loewy

Maurice (Moritz) Loewy (15 April 1833 – 15 October 1907) was a French astronomer.
Loewy was born in Vienna. Loewy's Jewish parents moved to Vienna in 1841 to escape the antisemitism of their home town. Loewy became an assistant at the Vienna Observatory, working on celestial mechanics. However, the institutions of Austria-Hungary did not permit a Jew to advance to a senior position without renouncing his faith and embracing Catholicism. The director of the observatory Karl L. Littrow was a correspondent of Urbain Le Verrier, director of the Paris Observatory and he secured a position there for Loewy in 1860. After going to France, Loewy become a naturalised French citizen.
He worked on the orbits of asteroids and comets and on the measurement of longitude, improving the accuracy of the "Connaissance des Temps". He also worked on optics and the elimination of the aberration of light.
He was elected a member of the Bureau des Longitudes in 1872 and of the Académie des Sciences in 1873.
Loewy became director of the Paris Observatory in 1896, reorganising the institution and establishing a department of physical astronomy. He further spent a decade working with Pierre Puiseux on an atlas of the Moon composed of 10,000 photographs, "L’Atlas photographique de la Lune" (1910), the definitive basis for lunar geography for over half a century. The crater Loewy on the Moon is named after him and asteroid 253 Mathilde is believed to be named after his wife.
He died in Paris at a government meeting of a sudden and unanticipated cardiac arrest.


Marratt and Ellis Opticians

Marratt & Ellis Opticians was a company established in 1828 in London, England. Initially known as J S Marratt, then Marratt and Short, this optician's was situated at 63 King William Street, the northern end of London Bridge where King William Street meets Gracechurch Street. Marratt and Ellis was at one time a large business engaged in sight testing, dispensing spectacles, making artificial eyes and a supplier of optical and scientific instruments. There are many examples of opera glasses, thermometers, barometers and meteorological instruments etc. which are engraved with the company name.
History.
IN 1828 a business was established in the City of London by the oculist J S Marratt.
In 1851, Marratt participated in the Great Exhibition of 1851 at Hyde Park, and was listed as an instrument maker.
In 1859, the company was known as Marratt and Short, and one of its proprietors was Thomas W. Short. That year the premises of the company were the subject of a scientific study of the toxicity of arsenic-impregnated green wallpaper which was popularly used at the time. Marratt and Short in 1862 also helped to develop an improved version of the laryngoscope.
A war damaged book of the company's accounts running from October 1857 to July 1866 shows the business doing well, maintaining takings between £300 to £400 a month. During the first six months of 1862 the figures were boosted to £500 by the sale of tickets to the Crystal Palace at its new site on a hill overlooking Sydenham, SE London.
In 1866, Short, working with an inventor named George Ansell, created an alarm system which would alert miners to the infiltration of gases. Short left the partnership in 1867.
Marratt then took on another partner, George Everest Ellis. This partnership was dissolved in 1880; however, the company continued to be called Marratt and Ellis. The company developed a line of artificial eyes, and exhibited at the International Medical and Sanitary Exhibition in 1881.
Although John Symonds Marratt died in Streatham in 1889, the company continued to operate under this name for many years. There are references to the business in The Illustrated London Progress Commerce in 1893. The business was operated by John Clement Ellis; according to the "Optician" Centenary Supplement 1991 stated that Mr J Ellis was considered a pioneer in sight-testing methods.
In 1914 G. E. Ellis was still connected with the company; he also represented the ward of Warwick on the Common Council of the City of London.
In May 1941, during World War Two, the premises suffered total destruction when a high explosive bomb landed nearby. The business reopened in various addresses in the City (Arthur Street, Eastcheap and Great Tower Street). John Clement Ellis, a batchelor, died intestate in 1952 at Wisborough Green, Sussex.
During the 1960s the business relocated to Forest Hill, SE London under the ownership of Wallis Cupit, at 14 Dartmouth Road. A letter from the manager of Westminster Bank Lombard Street dated 1961 invited the owner to lunch as their records show that Marratt and Ellis had held an account there for 84 years and they had never met.
Chris Watts took over the practice in 1974 and moved the business in 1994 to 50 London Road.
In 2007 the business was acquired by Johann Blandford and Alnoor Kassam and the name changed to Kassford Opticians. This was an amalgamation of their surnames. Johann and Alnoor still run the practice to this day at the 50 London Road address.
Photographs.
In 1844, a granite statue of King William IV, sculpted by Samuel Nixon, was erected at the intersection to the memory of the Sailor King. During this period, pictorial records of the statue, with the opticians directly behind, show how the area developed from the 1830s to the 1940s and prints and later photographs, show the changing life, and transport from hand carts to horse-drawn carriages, trolley buses and finally motor vehicles. These prints of the original engravings can be seen at the British Library, and many photos are in the Francis Frith Collection. The statue was moved to Greenwich Park in 1935.


Francesco Fontana

Francesco Fontana (, Naples – July 1656, Naples) was an Italian lawyer and an astronomer.
Francesco Fontana studied law at the University of Naples and then he became a lawyer in the court at the Castel Capuano. But failing to always find truth in the Court, he began to study mathematics and astronomy.
He created woodcuts showing the Moon and the planets as he saw them through a self-constructed telescope.
Fontana traced, in 1636, the first drawing of Mars and discovered its rotation.
In February 1646 he published the book "Novae coelestium terrestriumq[ue] rerum observationes, et fortasse hactenus non vulgatae", where he presented all the observations of the Moon made from 1629 until 1645, the drawings of the bands seen on Jupiter's disc, the strange appearances of Saturn, as well as of the stars of the Milky Way.
With a Fontana's telescope, the Jesuit Giovanni Battista Zupi observed for the first time in 1630 the horizontal bands on the atmosphere of Jupiter and in 1639 the phases of Mercury, an evidence, together with the phases of Venus observed by Galileo in 1610, that the Copernicus's heliocentric theory was correct.
In 1645, he claimed to have observed a satellite of Venus (Paul Stroobant demonstrated in 1887 that all similar observations were not related to a putative satellite of Venus).
He died of plague in Naples with the whole family in July 1656.
The lunar crater Fontana and the crater Fontana on Mars are named in his honor.
Note: See Donato Creti for paintings of planets from the next century.
Microscope.
Fontana also claimed to have invented the compound microscope (two or more lenses in a tube) in 1618, an invention that has many claimants including Cornelis Drebbel, Zacharias Jansen or his father Hans Martens, and Galileo Galilei.


March 2026 lunar eclipse

A total lunar eclipse will take place on March 3, 2026.
Visibility.
It will be completely visible over the Pacific, western USA and Canada, and New Zealand, will be seen rising over Australia and Asia, and setting over the rest of the Americas.
Related eclipses.
Saros series.
This lunar eclipse is part of series 133 of the Saros cycle, which repeats every 18 years and 11 days. Series 133 runs from the year 1557 until 2819. The previous eclipse of this series occurred on February 21, 2008 and the next will occur on March 13, 2044.
It is the 7th of 21 total lunar eclipses in series 133. The first was on December 28, 1917. The last (21st) will be on August 3, 2278. The longest two occurrences of this series (14th and 15th) will last for a total of 1 hour and 42 minutes on May 18, 2152 and May 30, 2170. Solar saros 140 interleaves with this lunar saros with an event occurring every 9 years 5 days alternating between each saros series.
Half-Saros cycle.
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse is related to two annular solar eclipses of Solar Saros 140.


Suzanne Smrekar

Suzanne E. Smrekar is an American astronomer and Deputy Principal Investigator for the Mars InSight lander.
Background.
Smrekar obtained her B.S. degree in geophysics and mathematics from Brown University in 1984, and her doctorate in geophysics from Southern Methodist University in 1990. She was an postdoctoral researcher at MIT before joining the Jet Propulsion Laboratory (JPL) in 1992.
Career.
Published works.
Smrekar and colleague Ellen Stofan reported in "Science" in 1997 that Venus' heat loss was caused by volcanic activity and formations specific to Venus. As Venus has no plate tectonics like Earth, she and others are attempting to study its volcanalogy to draw better conclusions about formation of Earth. Smrekar and an international team of researchers presented the Venus Emissivitiy Mapper (VEM) at a conference in 2018; this device scans the planet's surface at specific wavelengths to record the mineral composition, and uses other channels to determine cloud cover, weather, interference, and volcanic activity.
Smrekar remains a team member of the joint Brown - MIT NASA Lunar Science Institute. She has jointly written several articles for the Encyclopedia of the Solar System.
NASA Missions.
Smrekar has formed part of multiple NASA teams dedicated to exploring the Solar System. In 1999, she was involved with the design of the ground-penetrant micro-laboratories Deep Space 2 that "hitchhiked" on the Mars Polar Lander. She was Deputy Project Leader for the Mars Reconnaissance Orbiter (MRO), which, in addition to monitoring the eventual descent for multiple Martian instrument landings, used its shallow- and deep-penetration radar to uncover a pool of solid carbon dioxide at Mars' South Pole - "equivalent to Lake Superior." Direct observation of the Martian lithosphere led to some of the first accurate measurements of the interior temperature of the planet. Her Magellan probe uncovered newly-active geology on the planet. She designed the HP3 and GEMS instrument packages for the InSight mission, which commenced in 2016. Smrekar served as Deputy Principal Investigator in addition to constructing much of the ground-penetrant instrumentation for InSight. She lightly referred to needing to obtain sub-surface results of Martian geography and geology as understanding "...the whole enchilada" of non-Earth planets.
Minor planet discoverer.
On 14 June 1983, Smrekar discovered asteroid 6819 McGarvey at Palomar Observatory. She named it after her mother Flora McGarvey Smrekar (1924–1977).


Edward Pigott

Edward Pigott (1753–1825) was an English astronomer notable for being one of the founders of the study of variable stars.
Biography.
Son of the astronomer Nathaniel Pigott, Pigott's work focused on variable stars. Educated in France with a mother from Louvain, the family moved to York in 1781. Despite their significant age difference, he was a friend and collaborator of John Goodricke (his distant cousin) until the latter's untimely death at the age of 21 in 1786.
In 1784, Pigott informed the Royal Society of his discovery of a new variable star. This was Eta Aquilae which he had identified the previous year. He corresponded with leading astronomers of the day including William Herschel and Nevil Maskelyne.
Pigott moved to Bath in 1796. Pigott's notebooks survive at York City Archives.
Honors.
Asteroid 10220 Pigott is named after Edward and his father. It was discovered by R. A. Tucker at the observatory in Tucson, Arizona which bears Pigott's name and that of his friend Goodricke.


Marco Cavagna

Marco Cavagna (1958 – August 9, 2005) was an Italian amateur astronomer.
During his career, Cavagna discovered numerous asteroids, operating from the Sormano Astronomical Observatory in Sormano, northern Italy. The Minor Planet Center credits him with the discovery of 19 minor planets he made between 1994 and 1998. In the 1970s and 1980s, he was one of Italy's leading observers of comets and national coordinator during the International Halley Watch in 1986. Cavagna was also a lecturer at the planetarium of Milan, co-founder of the Sormano Observatory, and a consultant for IAU's commission XX (Positions & motions of minor planets, comets and satellites).
Cavagna died of a stroke on 9 August 2005. The 0.5-meter Ritchey–Chrétien telescope at Sormano Observatory is now named in his memory. The inner main-belt asteroid 10149 Cavagna, discovered by astronomers Maura Tombelli and Andrea Boattini at San Marcello Pistoiese Observatory, was named after him in 1999 ().


Gabriel Delmotte

Gabriel Delmotte (5 February 1876 – 10 March 1950) was a French astronomer, deputy and Mayor of Masnières in the Nord department in northern France.
He was the author of "Recherches sélénographiques et nouvelle théorie des cirques lunaires", which was published in 1923 in Paris.
The crater Delmotte on the Moon is named after him.


Ellen Gould Zweibel

Ellen Gould Zweibel (born 20 December 1952, New York City) is an American astrophysicist and plasma physicist.
In 1973, Zweibel received her bachelor's degree in mathematics from the University of Chicago and in 1977 her Ph.D. in physics from Princeton with thesis "The Equilibrium and Radial Oscillations of Cool Stellar Disks" under the supervision of Jeremiah P. Ostriker. She was a visiting scholar at the Institute for Advanced Study for the academic year 1977–1978 and then joined the solar physics group of the High Altitude Observatory of the National Center for Atmospheric Research. In addition, she was from 1980 to 2003 a professor at the University of Colorado. She is now the William L. Kraushaar Professor of Astronomy and Physics at the University of Wisconsin–Madison. Zweibel is a founding member and former director of the Center of Magnetic Self-Organization of the National Science Foundation (NSF) and of the Department of Energy (DOE).
Recognition.
In 1991, she was elected a Fellow of the American Physical Society.
In 2016, she received the James Clerk Maxwell Prize for Plasma Physics for "seminal research on the energetics, stability, and dynamics of astrophysical plasmas, including those related to stars and galaxies, and for leadership in linking plasma and other astrophysical phenomena". She investigates astrophysical phenomena and plasmas physics of the sun, stars, galaxies, and clusters of galaxies.
She was elected to the National Academy of Sciences in 2021.


Gillian Foulger

Gillian Rose Foulger is a British geologist and academic born in 1952 in Ipswich. Foulger plays a major role in coordinating the global debate in the category of Earth Science, on whether or not deep mantle thermal plumes exist and create “hot spot” volcanism.
Biography.
Foulger is a Professor of Geophysics at Durham University, where she completed her doctorate in 1985 and her Master of Science in Geophysics degree in 1976. She also received an M.A in 1978 and a B.A in Natural Sciences in 1974 both from the University of Cambridge. She is one of the leading proponents of alternative models, such as plate theory, to the established deep mantle thermal plume hypothesis. Foulger is a Managing Editor of Earth-Science Reviews; Scientific Reports Journal, a journal that publishes review articles of Earth Sciences.
Hot spots and mantle plumes
Challenging the mantle plume hypothesis, Foulger has posited that there is no chemical or isotopic data that require deep-plume origins nor are there anomalously elevated temperatures indicating the existence of such. She further claims that reliable seismic-tomography results have yet to reveal concrete evidence of a plume. Plumes, in her estimation, cannot therefore account for the eruption rates of the largest flood basalts, which she suggests could be explained alternatively by rapidly draining reservoirs of molten rock that have accumulated over time. Her research represents significant progress in developing an alternative model for anomalous volcanism. This phenomenon, she has suggested, can be better explained as a passive reaction to the stretching of lithospheric plates — such as in rift valleys — which allows melt to rise from shallow depths in the mantle. This work makes for an important contribution to the understanding of volcanic and earthquake areas such as the Hawaii, Iceland and Yellowstone hotspots.
Foulger has suggested that, regarding the mantle plume controversy in Earth Science, the fundamental reasons for the ongoing developments of this controversy are not well established. These factors according to Foulger are as follows: firstly, many observations conflict with the predictions of the original model. Secondly, that it is possible that the sort of convection necessary to generate thermal plumes in the Earth’s mantle does not occur. Thirdly, that so many variants of the original model have been invoked to accommodate what she describes as conflicting data, that the plume hypothesis is in practice no longer testable; finally, that alternative models are viable, though she suggests that these alternatives have been largely neglected by researchers.
Time-dependent seismic topography of the Coso geothermal area
From 1996-2004 Gillian Foulger, along with others such as Bruce Julian, Keith Richards-Dinger, and Francis Monastero monitored seismic activity using the arrival times of the U.S Navy's seismometer network in the Coso Volcanic Field's geothermal area in California, in order to calculate the local-earthquake topography images. The Coso geothermal area in which this project takes place is used by to produce ~250 megawatts of electricity. This project, created through the collaboration of the United States Geological Survey, the U.S Navy and the University of Utah, as well as funds from the United States Department of Energy has created a set of data in which numerous other studies have the potential to be produced. Foulger has used this ~80,000-earthquake dataset to analyze time-dependent seismic tomography, relative event relocations and moment-tensor analysis and aid in developing energy production strategies.
Awards and Honours.
1993, Nuffield Foundation fellow.
2001, Sir James Knott research Fellow.
2005, Foulger was made a Fellow of the Icelandic National Academy of Sciences.
2005, awarded the Price Medal for her work in "for investigations of outstanding merit in solid-earth geophysics, oceanography, or planetary sciences" of the Royal Astronomical Society.
2015, Fellow of the Geological Society of America.
2020, Foulger was awarded the Leopold Von Buch Badge by the German Geological Society for her research in earthquake seismology and plate tectonics, in which her research also confronted long held assumptions of the way mantles work and how volcanoes were formed.
Society Memberships.
Foulger is a member of 6 different scientific societies; she is a Fellow of the Icelandic National Academy of Sciences, Fellow of the Royal Astronomical Society, a member of the American Geophysical Union, a Fellow of the Geological Society of America, a member of the Society of Exploration Geophysicists, and a member of the International Association of Geodesy.


Hypergiant

A hypergiant (luminosity class 0 or Ia+) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of their extreme stellar winds. The term "hypergiant" is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in the literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia+, but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially with star formation, stability, and their expected demise as supernovae.
Origin and definition.
In 1956, the astronomers Feast and Thackeray used the term "super-supergiant" (later changed into hypergiant) for stars with an absolute magnitude brighter than "M"V = −7 ("M"Bol will be larger for very cool and very hot stars, for example at least −9.7 for a B0 hypergiant). In 1971, Keenan suggested that the term would be used only for supergiants showing at least one broad emission component in Hα, indicating an extended stellar atmosphere or a relatively large mass loss rate. The Keenan criterion is the one most commonly used by scientists today.
To be classified as a hypergiant, a star must be highly luminous and have spectral signatures showing atmospheric instability and high mass loss. Hence it is possible for a non-hypergiant, supergiant star to have the same or higher luminosity as a hypergiant of the same spectral class. Hypergiants are expected to have a characteristic broadening and red-shifting of their spectral lines, producing a distinctive spectral shape known as a P Cygni profile. The use of hydrogen emission lines is not helpful for defining the coolest hypergiants, and these are largely classified by luminosity since mass loss is almost inevitable for the class.
Formation.
Stars with an initial mass above about quickly move away from the main sequence and increase somewhat in luminosity to become blue supergiants. They cool and enlarge at approximately constant luminosity to become a red supergiant, then contract and increase in temperature as the outer layers are blown away. They may "bounce" backwards and forwards executing one or more "blue loops", still at a fairly steady luminosity, until they explode as a supernova or completely shed their outer layers to become a Wolf–Rayet star. Stars with an initial mass above about are simply too luminous to develop a stable extended atmosphere and so they never cool sufficiently to become red supergiants. The most massive stars, especially rapidly rotating stars with enhanced convection and mixing, may skip these steps and move directly to the Wolf–Rayet stage.
This means that stars at the top of the Hertzsprung–Russell diagram where hypergiants are found may be newly evolved from the main sequence and still with high mass, or much more evolved post-red supergiant stars that have lost a significant fraction of their initial mass, and these objects cannot be distinguished simply on the basis of their luminosity and temperature. High-mass stars with a high proportion of remaining hydrogen are more stable, while older stars with lower masses and a higher proportion of heavy elements have less stable atmospheres due to increased radiation pressure and decreased gravitational attraction. These are thought to be the hypergiants, near the Eddington limit and rapidly losing mass.
The yellow hypergiants are thought to be generally post-red supergiant stars that have already lost most of their atmospheres and hydrogen. A few more stable high mass yellow supergiants with approximately the same luminosity are known and thought to be evolving towards the red supergiant phase, but these are rare as this is expected to be a rapid transition. Because yellow hypergiants are post-red supergiant stars, there is a fairly hard upper limit to their luminosity at around , but blue hypergiants can be much more luminous, sometimes several million .
Almost all hypergiants exhibit variations in luminosity over time due to instabilities within their interiors, but these are small except for two distinct instability regions where luminous blue variables (LBVs) and yellow hypergiants are found. Because of their high masses, the lifetime of a hypergiant is very short in astronomical timescales: only a few million years compared to around 10 billion years for stars like the Sun. Hypergiants are only created in the largest and densest areas of star formation and because of their short lives, only a small number are known despite their extreme luminosity that allows them to be identified even in neighbouring galaxies. The time spent in some phases such as LBVs can be as short as a few thousand years.
Stability.
As the luminosity of stars increases greatly with mass, the luminosity of hypergiants often lies very close to the Eddington limit, which is the luminosity at which the radiation pressure expanding the star outward equals the force of the star's gravity collapsing the star inward. This means that the radiative flux passing through the photosphere of a hypergiant may be nearly strong enough to lift off the photosphere. Above the Eddington limit, the star would generate so much radiation that parts of its outer layers would be thrown off in massive outbursts; this would effectively restrict the star from shining at higher luminosities for longer periods.
A good candidate for hosting a continuum-driven wind is Eta Carinae, one of the most massive stars ever observed. With an estimated mass of around 130 solar masses and a luminosity four million times that of the Sun, astrophysicists speculate that Eta Carinae may occasionally exceed the Eddington limit. The last time might have been a series of outbursts observed in 1840–1860, reaching mass loss rates much higher than our current understanding of what stellar winds would allow.
As opposed to line-driven stellar winds (that is, ones driven by absorbing light from the star in huge numbers of narrow spectral lines), continuum driving does not require the presence of "metallic" atoms — atoms other than hydrogen and helium, which have few such lines — in the photosphere. This is important, since most massive stars also are very metal-poor, which means that the effect must work independently of the metallicity. In the same line of reasoning, the continuum driving may also contribute to an upper mass limit even for the first generation of stars right after the Big Bang, which did not contain any metals at all.
Another theory to explain the massive outbursts of, for example, Eta Carinae is the idea of a deeply situated hydrodynamic explosion, blasting off parts of the star's outer layers. The idea is that the star, even at luminosities below the Eddington limit, would have insufficient heat convection in the inner layers, resulting in a density inversion potentially leading to a massive explosion. The theory has, however, not been explored very much, and it is uncertain whether this really can happen.
Another theory associated with hypergiant stars is the potential to form a pseudo-photosphere, that is a spherical optically dense surface that is actually formed by the stellar wind rather than being the true surface of the star. Such a pseudo-photosphere would be significantly cooler than the deeper surface below the outward-moving dense wind. This has been hypothesized to account for the "missing" intermediate-luminosity LBVs and the presence of yellow hypergiants at approximately the same luminosity and cooler temperatures. The yellow hypergiants are actually the LBVs having formed a pseudo-photosphere and so apparently having a lower temperature.
Relationships with Ofpe, WNL, LBV, and other supergiant stars.
Hypergiants are evolved, high luminosity, high-mass stars that occur in the same or similar regions of the HR diagram to stars with different classifications. It is not always clear whether the different classifications represent stars with different initial conditions, stars at different stages of an evolutionary track, or is just an artifact of our observations. Astrophysical models explaining the phenomena show many areas of agreement. Yet there are some distinctions that are not necessarily helpful in establishing relationships between different types of stars.
Although most supergiant stars are less luminous than hypergiants of similar temperature, a few fall within the same luminosity range. Ordinary supergiants compared to hypergiants often lack the strong hydrogen emissions whose broadened spectral lines indicate significant mass loss. Evolved lower mass supergiants do not return from the red supergiant phase, either exploding as supernovae or leaving behind a white dwarf.
Luminous blue variables are a class of highly luminous hot stars that display characteristic spectral variation. They often lie in a "quiescent" zone with hotter stars generally being more luminous, but periodically undergo large surface eruptions and move to a narrow zone where stars of all luminosities have approximately the same temperature, around 8,000K. This "active" zone is near the hot edge of the unstable "void" where yellow hypergiants are found, with some overlap. It is not clear whether yellow hypergiants ever manage to get past the instability void to become LBVs or explode as a supernova.
Blue hypergiants are found in the same parts of the HR diagram as LBVs but do not necessarily show the LBV variations. Some but not all LBVs show the characteristics of hypergiant spectra at least some of the time, but many authors would exclude all LBVs from the hypergiant class and treat them separately. Blue hypergiants that do not show LBV characteristics may be progenitors of LBVs, or vice versa, or both. Lower mass LBVs may be a transitional stage to or from cool hypergiants or are different type of object.
Wolf–Rayet stars are extremely hot stars that have lost much or all of their outer layers. WNL is a term used for late stage (i.e. cooler) Wolf–Rayet stars with spectra dominated by nitrogen. Although these are generally thought to be the stage reached by hypergiant stars after sufficient mass loss, it is possible that a small group of hydrogen-rich WNL stars are actually progenitors of blue hypergiants or LBVs. These are the closely related Ofpe (O-type spectra plus H, He, and N emission lines, and other peculiarities) and WN9 (the coolest nitrogen Wolf–Rayet stars) which may be a brief intermediate stage between high mass main-sequence stars and hypergiants or LBVs. Quiescent LBVs have been observed with WNL spectra and apparent Ofpe/WNL stars have changed to show blue hypergiant spectra. High rotation rates cause massive stars to shed their atmospheres quickly and prevent the passage from main sequence to supergiant, so these directly become Wolf–Rayet stars. Wolf Rayet stars, slash stars, cool slash stars (aka WN10/11), Ofpe, Of+, and Of* stars are not considered hypergiants. Although they are luminous and often have strong emission lines, they have characteristic spectra of their own.
Known hypergiants.
Hypergiants are difficult to study due to their rarity. Many hypergiants have highly variable spectra, but they are grouped here into broad spectral classes.
Luminous blue variables.
Some luminous blue variables are classified as hypergiants, during at least part of their cycle of variation:
Blue hypergiants.
Usually B-class, occasionally late O or early A:
In Galactic Center Region:
In Westerlund 1:
Yellow hypergiants.
Yellow hypergiants with late A -K spectra:
In Westerlund 1:
In the Triangulum Galaxy:
In the Sextans galaxy:
Plus at least two probable cool hypergiants in the recently discovered Scutum Red Supergiant Clusters: F15 and possibly F13 in RSGC1 and Star 49 in RSGC2.
Red hypergiants.
M type spectra, the largest known stars:


Bosscha Observatory

Bosscha Observatory is the oldest modern observatory in Indonesia, and one of the oldest in Asia. The observatory is located in Lembang, West Java, approximately north of Bandung. It is situated on a hilly six hectares of land and is above mean sea level plateau. The IAU observatory code for Bosscha is 299.
History.
During the first meeting of the "Nederlandsch-Indische Sterrekundige Vereeniging" (Dutch-Indies Astronomical Society) in the 1920s, it was agreed that an observatory was needed to study astronomy in the Dutch East Indies. Of all locations in the Indonesia archipelago, a tea plantation in Malabar, a few kilometers north of Bandung in West Java was selected. It is on the hilly north side of the city with a non-obstructed view of the sky and with close access to the city that was planned to become the new capital of the Dutch colony, replacing Batavia (present-day Jakarta). The observatory is named after the tea plantation owner Karel Albert Rudolf Bosscha, son of the physicist Johannes Bosscha and a major force in the development of science and technology in the Dutch East Indies, who granted six hectares of his property for the new observatory.
Construction of the observatory began in 1923 and was completed in 1928. Since then a continuous observation of the sky was made. The first international publication from Bosscha was published in 1922. Observations from Bosscha were halted during World War II and after the war a major reconstruction was necessary. On 17 October 1951, the Dutch-Indies Astronomical Society handed over operation of the observatory to the government of Indonesia. In 1959 the observatory's operation was given to the Institut Teknologi Bandung and has been an integral part of the research and formal education of astronomy in Indonesia.
Facilities.
Five large telescopes were installed in Bosscha:
Directors.
1923 - 1940 : Dr. J. Voûte

1940 - 1942 : Dr. Aernout de Sitter

1942 - 1946 : Prof. Dr. Masashi Miyaji

1946 - 1949 : Prof. Dr. J. Hins

1949 - 1958 : Prof. Dr. Gale Bruno van Albada

1958 - 1959 : Prof. Dr. Ong Ping Hok, Dr. Kusumanto Purbosiswoyo (1959-1960) and Santoso Nitisastro (temporary officers)

1959 - 1968 : Prof. Dr. The Pik Sin

1968 - 1999 : Prof. Dr. Bambang Hidayat

1999 - 2004 : Dr. Moedji Raharto

2004 - 2006 : Dr. Dhani Herdiwijaya

2006 - 2009 : Prof. Dr. Taufiq Hidayat

2009 - 2012 : Dr. Hakim L. Malasan

2012 - 2018: Dr. Mahasena Putra

2018 - "present": Dr. Premana W Primadi
In popular culture.
The popular American reality TV Series "The Amazing Race 23" used this site as a Pit Stop for its 9th leg. The episode that used this site for filming was nominated for the Emmys in several categories and won the Outstanding Reality-Competition Program award.


Karl Stumpff

Karl Johann Nikolaus Stumpff (May 17, 1895 – November 10, 1970) was a German astronomer. The Stumpff functions, used in the universal variable formulation of the two-body problem, are named after him.


BalloonSat


Barwell meteorite


Observatory of Strasbourg

The Observatory of Strasbourg is an astronomical observatory in Strasbourg, France.
Following the Franco-Prussian War of 1870–71, the city of Strasbourg became part of the German Empire. The University of Strasbourg was refounded in 1872 and a new observatory began construction in 1875 in the Neustadt district. The main instrument was a 50 cm Repsold refractor, which saw first light in 1880 (see Great refractor). At the time this was the largest instrument in the German Empire. In 1881, the ninth General Assembly of the Astronomische Gesellschaft met in Strasbourg to mark the official inauguration.
The observatory site was selected primarily for instruction purposes and political symbolism, rather than the observational qualities. It was a low-lying site that was prone to mists. During the period up until 1914, the staff was too small to work the instruments and so there was little academic research published prior to World War I. The main observations were of comets and variable stars. After 1909, the instruments were also used to observe binary stars and perform photometry of nebulae.
The observatory is currently the home for the Centre de données astronomiques de Strasbourg, a database for the collection and distribution of astronomical information. This includes SIMBAD, a reference database for astronomical objects, VizieR, an astronomical catalogue service and Aladin, an interactive sky atlas. The modern extension of the building houses Planétarium de Strasbourg. The observatory is surrounded by the Jardin botanique de l'Université de Strasbourg.
In the vaulted basement below the observatory, a University-administered museum is located. Called "Crypte aux étoiles" ("star crypt"), it displays old telescopes and other antique astronomical devices such as clocks and theodolites.


Carlo Antonio Manzini

Conte Carlo Antonio Manzini (1599–1677/1678) was an Italian astronomer and mathematician. (His last name is sometimes given as Mangini or Mansini.)
He was a member of the local nobility of Bologna. In 1626 he published "Tabulae primi mobilis: quibus nova dirigendi ars et praecipuè circuli positionis inventio, non minus facilis quam exacta ostenditur". This volume presented tables for the construction of astrological charts.
His 1660 work, "L'occhiale all'occhio, dioptrica practica", is one of the oldest accounts of the techniques for manufacturing lenses through grinding and polishing.
Sources list his year of death as 1677 or 1678. The crater Manzinus on the Moon is named after him.


Solar eclipses after the modern era

This article contains information and statistics about solar eclipses occurring after the modern era, from the 22nd century to the 30th century.
Longest total eclipses.
Below is a list of all total eclipses at least 7 minutes long that will occur between the 22nd and 30th centuries. Of the listed eclipses, the first five are in Solar Saros 139, the next three are in Solar Saros 145, and the final four are in Solar Saros 170.


Otto Boeddicker

Otto Boeddicker (1853–1937) was a German astronomer. He published drawings of naked-eye observations of the Milky Way in 1892, made over a period of six years. He also observed the Moon, including the emitted heat during a total eclipse of the Moon.
In 1880 he became the astronomical assistant of Lawrence Parsons, 4th Earl of Rosse at Birr Castle in Birr, Ireland, and remained in that position until the death of the Earl in 1908. He left for Germany in 1916 after being designated an enemy alien.
A crater on Mars is named in his honor.


Normanton Down Barrows

Normanton Down is a Neolithic and Bronze Age barrow cemetery located about south of Stonehenge in Wiltshire, England. The burials date from between 2600 and 1600 BC and consist of a Neolithic long barrow and some 40 or more Bronze Age round barrows, sited along the crest of a low ridge.
Excavations.
The barrows of Normanton Down, visible from Stonehenge along the southern horizon, have been part of the scenery of Salisbury Plain since 2000 BC. Barrow excavation was a popular hobby in the 18th and 19th centuries among amateur archaeologists, who became known as "barrow-diggers." In 1808, William Cunnington and Sir Richard Colt Hoare excavated several of the barrows, including the most important barrow, the Bush Barrow. Almost all of these barrows are believed to be from the Bronze Age, but several features, including a Long barrow, are earlier, dating to neolithic times. Cunnington and Hoare noted four sets of "curiously huddled together" human remains in the east end of the Long barrow. Unlike many of the early excavations, Hoare published a detailed account of their findings in 1812. South of the long barrow lies a mortuary enclosure; this rectangular neolithic earthwork, now ploughed out, was discovered by aerial photography and excavated in 1959.
Legal protection for many of the barrows was introduced in 1925 when they were designated a scheduled monument. The area was designated a World Heritage Site in 1987, since which excavation of any sort has been even more strictly controlled. Recent study has therefore focussed on re-appraising existing finds and non-intrusive fieldwork. In 2007, researchers from the University of Birmingham, funded by the Leverhulme Trust, began intensive studies of the artefacts found in all British Bronze Age burials, including those at Bush Barrow; and in 2010 an extensive survey of the condition and context of the barrows was made by English Heritage, as part of their Stonehenge World Heritage Site Landscape Project.
Development of the site.
The Normanton Down site reveals the development of an entire Bronze Age cemetery. 24 barrows are covered by 6 different Scheduled Monument designations, and a total of at least 35 surviving barrows were identified and numbered by L V Grinsell in 1957. They appeared gradually throughout the Bronze Age. Multiple graves all covered by a single barrow are characteristic of the area.
The early part of the Bronze Age was marked by Beaker burials, characteristic of the Beaker people. The Beaker graves contained various funerary goods and were usually covered by round barrows; however, most of these barrows did not survive, making the graves hard to locate. It is assumed that these Beaker burials are located mostly to the west, in areas marked by older long or oval barrows. Also, mounds were later erected over some of the preexisting Beaker graves, enabling early excavators to locate them.
Later, the layout of the cemetery changed dramatically. The Normanton "linear" cemetery emerged along the main ridge, with three foci marking the landscape in a relatively straight line. Even though it is very likely that each focus was previously a Beaker grave, there is a clear tendency towards building sizeable mounds. Grave clustering seems to be present to some extent, especially in one of the Beaker burials and in the Bush Barrow.
Although most of the barrows were constructed by the end of the Early Bronze Age, a significant change appears in the middle of the Bronze Age. Burials involving Deverel-Rimbury urns of middle Bronze Age manufacture are present in clusters of small mounds. In the same time period, the burials appear to decline on Normanton Down, possibly shifting west to the vicinity of a remarkable feature known as the Wilsford shaft, which is a deep shaft, within a mid-Bronze Age Pond barrow.
Bush Barrow.
The most famous burial mound at Normanton Down is called Bush Barrow and is 40m wide and 3m high. The name "Bush Barrow" was given to this archaeological site in the 1720s by William Stukeley because of the trees planted on the top. It was previously known as "the green barrow" for the same reason. It was excavated in 1808 by William Cunnington and Sir Richard Colt-Hoare, who found multiple artefacts inside the mound.
Cunnington wrote a detailed account of the discovery of a body and artefacts surrounding it in the barrow. He described that the head of the grave was at the south and the body was positioned on the floor rather than in a pit, which was considered unusual. In the account, Cunnington described pieces of brass and wood that are now believed to be the remains of a rare type of dagger or knife. Modern reconstructions have led to the conclusion that the artefacts were arranged closely around the body.
Below is an extract from Cunnington's account:
" On reaching the floor of the barrow, we discovered the skeleton of a stout and tall man lying from south to north: the extreme length of his thigh bone was 20 inches. About 18 inches south of the head we found several brass (i. e. bronze) rivets intermixed with wood and some thin bits of brass nearly decomposed. These articles covered a space of 12 inches or more; it is probable therefore that they were the mouldered remains of a shield. Near the right arm was a large dagger of brass and a spearhead of the same material, full 13 inches long, and the largest we have ever found. "
"Immediately over the breast of the skeleton was a large plate of gold, in the form of a lozenge and measuring 7 inches by 6 inches. The even surface of this noble ornament is relieved by indented lines, checks and zigzags, forming the shape of the outline, and forming lozenge within lozenge, diminishing gradually towards the centre. We next discovered, on the right side of the skeleton, a very curious perforated stone, some wrought articles of bone, many small rings of the same material and another lozenge of gold. As this stone bears no marks of wear or attrition, I can hardly consider it to have been used as a domestic implement, and from the circumstances of it being composed of a mass of seaworms or little serpents, I think we may not be too fanciful in considering it an article of consequence."
The finds from Bush Barrow are now displayed at the Wiltshire Museum in Devizes, which preserves the manuscript notes made by Cunnington and the drawings made by Philip Crocker.
Significance.
The type and quantity of grave goods found at Normanton Down suggest it was a burial place for people of high social status. Lavish burial configurations have also been identified. For example, the senior males found buried with daggers were originally placed in the grave lying on their left side. These males were most likely community leaders who toted daggers in their daily lives.
In addition, the location of Normanton Down as a whole suggests a special burial site. It was laid out with clear and commanding views of Stonehenge and other ridge tops in every direction (except the northwest), and it is crossed by the same solstitial axis that passes through Stonehenge. Further study of Normanton Down has revealed an absence of flint-working on the site relative to its immediately surrounding areas. It seems the location was set apart from everyday activities and most likely carried special significance.
Compared to other similar cemeteries, the Normanton Down location contains an uncommonly high number of disc barrows in addition to several bell barrows and one saucer barrow.


Lunar south pole

The lunar south pole is of special interest to scientists because of the occurrence of water ice in permanently shadowed areas around it. The lunar south pole region features craters that are unique in that the near-constant sunlight does not reach their interior. Such craters are cold traps that contain a fossil record of hydrogen, water ice, and other volatiles dating from the early Solar System. In contrast, the lunar north pole region exhibits a much lower quantity of similarly sheltered craters.
Geography.
The lunar south pole is located on the center of the polar Antarctic Circle (80°S to 90°S). The lunar south pole has shifted 5 degrees from its original position billions of years ago. This shift has changed the rotational axis of the Moon, allowing sunlight to reach previously shadowed areas, but the south pole still features some completely shadowed areas. The axis spin is 88.5 degrees from the plane of the elliptic. On the contrary, the pole also contains areas with permanent exposure to sunlight. The south pole region features many craters and basins such as the South Pole–Aitken basin, which appears to be one of the most fundamental features of the Moon, and mountains, such as Epsilon Peak at 9.050 km, taller than any mountain found on Earth. The south pole temperature averages at approximately .
Craters.
The rotational axis of the Moon lies within Shackleton Crater. Notable craters nearest to the lunar south pole include De Gerlache, Sverdrup, Shoemaker, Faustini, Haworth, Nobile, and Cabeus.
Discoveries.
Illumination.
The lunar south pole features a region with crater rims exposed to near constant solar illumination, yet the interior of the craters are permanently shaded from sunlight. The area's illumination was studied using high resolution digital models produced from data by the Lunar Reconnaissance Orbiter. The lunar surface can also reflect solar wind as energetic neutral atoms. On average, 16% of these atoms have been protons that varies based on location. These atoms have created an integral flux of backscattered hydrogen atoms due to the reflected amount of plasma that exists on the surface of the Moon. They also reveal the line boundary and the magnetic dynamics within the regions of these neutral atoms on the Moon' surface.
Cold traps.
Cold traps are some of the important places on the lunar south pole region in terms of possible water ice and other volatile deposits. Cold traps can contain water and ice that were originally from comets, meteorites and solar wind-induced iron reduction. From experiments and sample readings, scientists were able to confirm that cold traps do contain ice. Hydroxyl has also been found in these cold traps. The discovery of these two compounds has led to the funding of missions focusing primarily on the lunar poles using global scale infrared detection. The ice stays in these traps because of the thermal behavior of the Moon that are controlled by thermophysical properties such as scattered sunlight, thermal re-radiation, internal heat and light given off by the Earth.
Magnetic surface.
There are areas of the Moon where the crust is magnetized. This is known as a magnetic anomaly due to the remnants of metal iron that was emplaced by the impactor that formed the South Pole–Aitken basin (SPA basin). However, the concentration of iron that is thought to be in the basin was not present in the mappings, as they could be too deep in the Moon's crust for the mappings to detect. Or the magnetic anomaly is caused by another factor that does not involve metallic properties. The findings were proven inadequate due to the inconsistencies between the maps that were used, and also, they were not able to detect the magnitude of the magnetic fluctuations at the Moon's surface.
Exploration.
Missions.
Orbiters from several countries have explored the region around the lunar south pole. Extensive studies were conducted by the Lunar Orbiters, Clementine, Lunar Prospector, Lunar Reconnaissance Orbiter, Kaguya, and Chandrayaan-1, that discovered the presence of lunar water. NASA's LCROSS mission found a significant amount of water in Cabeus. NASA's LCROSS mission deliberately crashed into the floor of Cabeus and from samples found that it contained nearly 5% water.
The Lunar Reconnaissance Orbiter (LRO) was launched on 18 June 2009 and is still mapping the lunar south pole region. This mission will help scientists see if the lunar south pole region has enough sustainable resources to sustain a permanent crewed station. The LRO carries the Diviner Lunar Radiometer Experiment, which is investigating the radiation and thermophysical properties of the south pole surface. It can detect reflected solar radiation and internal infrared emissions. The LRO Diviner is able to detect where water ice could be trapped on the surface.
On , the Chang'e 4, a Chinese spacecraft, was the first to soft land (45.5 ° S, 177.6 ° E) in the Von Kármán crater, which is within the immense South Pole-Aitken Basin on the southern far side of the Moon.
India's second lunar mission Chandrayaan-2, which was launched on 22 July 2019, attempted to soft-land on the south polar region of the Moon between 70.90267°S 22.78110°E and 67.87406°S 18.46947°W. The lander failed to land safely, losing communication barely 335m from the ground.
Role in the future exploration and observations.
The lunar south pole region is deemed as a compelling spot for future exploration missions and suitable for a lunar outpost. The permanently shadowed places on the Moon could contain ice and other minerals, which would be vital resources for future explorers. The mountain peaks near the pole are illuminated for large periods of time and could be used to provide solar energy to an outpost. With an outpost on the Moon scientists will be able to analyze water and other volatile samples dating back to the formation of the Solar System.
Scientists used LOLA (Lunar Orbiter Laser Altimeter), which was a device used by NASA to provide an accurate topographic model of the Moon. With this data locations near the south pole at Connecting Ridge, which connects Shackleton Crater to the de Gerlache crater, were found that yielded sunlight for 92.27–95.65% of the time based on altitude ranging from 2 m above ground to 10 m above ground. At the same spots it was discovered that the longest continuous periods of darkness were only 3 to 5 days.
The lunar south pole is a place where scientists may be able to perform unique astronomical observations of radio waves under 30 MHz. The Chinese "Longjiang" microsatellites were launched in May 2018 to orbit the Moon, and "Longjiang-2" operated in this frequency until 31 July 2019. Before "Longjiang-2", no space observatory had been able to observe astronomical radio waves in this frequency because interference waves from equipment on Earth. The lunar south pole has mountains and basins that are not facing Earth and would be an ideal place to receive such astronomical radio signals from a ground radio observatory.
Resources.
Solar power, oxygen, and metals are abundant resources on the south polar region. By locating a lunar resource processing facility near the south pole, solar-generated electrical power will allow for nearly constant operation. Elements known to be present on the lunar surface include, among others, hydrogen (H), oxygen (O), silicon (Si), iron (Fe), magnesium (Mg), calcium (Ca), aluminium (Al), manganese (Mn) and titanium (Ti). Among the more abundant are oxygen, iron and silicon. The oxygen content is estimated at 45% (by weight).
Future.
Blue Origin is planning a mission to the south polar region in about 2024. The "Blue Moon" lander derives from the vertical landing technology used in Blue Origin's New Shepard sub-orbital rocket. This would lead to a series of missions landing equipment for a crewed base in a south polar region crater using their Blue Moon lander.
NASA's Artemis program has proposed to land several robotic landers and rovers (CLPS) in preparation for the 2024 Artemis 3 crewed landing at the south polar region.


List of asteroid close approaches to Earth

This is a list of examples where an asteroid or meteoroid travels close to the Earth. Some are regarded as potentially hazardous objects if they are estimated to be large enough to cause regional devastation.
Near-Earth object detection technology greatly improved about 1998, so objects being detected as of 2004 could have been missed only a decade earlier due to a lack of dedicated near-Earth astronomical surveys. As sky surveys improve, smaller and smaller asteroids are regularly being discovered. The small near-Earth asteroids , 2014 AA, 2018 LA and 2019 MO are the only four asteroids discovered before impacting into Earth (see asteroid impact prediction). Scientists estimate that several dozen asteroids in the size range fly by Earth at a distance closer than the moon every year, but only a fraction of these are actually detected.
Timeline of approaches within one lunar distance.
The average distance to the Moon (or lunar distance (LD)) is about , which is around 30 times the diameter of the Earth. Below are lists of close approaches less than one LD for a given year. (See also near-Earth asteroids published by the International Astronomical Union and NEO Earth Close Approaches.)
Closest known per year.
From the list in the first section, these are the closest-known asteroids per year that approach Earth within one lunar distance. More than one asteroid per year may be listed if its geocentric distance is within a tenth of the lunar distance, or 0.10 LD. For comparison, since a satellite in a geostationary orbit has an altitude of about , then its geocentric distance is 0.11 LD (approximately three times the width of the Earth).
The table shows that the years 2016 and 2017 had a total of 13 such close encounters that are known. Of these, eight were undetected until after they'd happened and only one was detected with more than 24 hours' notice. 2018 has fared better so far, with six out of the eight known close encounters being detected beforehand, albeit with less than 24 hours' notice in most cases.
This list does not include any of the hundreds of objects that collided with Earth, which were not discovered in advance, but were recorded by sensors designed to detect detonation of nuclear devices. Of the objects so detected, 78 had an impact energy greater than that of a 1-kiloton device (equivalent to 1000 tons of TNT), including 11 which had an impact energy greater than that of a 10-kiloton device i.e. comparable to the atomic bombs used in the Second World War.
 Rows highlighted red indicate objects which were not discovered until after closest approach
 Rows highlighted yellow indicate objects discovered less than 24 hours before closest approach
 Rows left white indicate objects discovered 1–7 days before closest approach
 Rows highlighted green indicate objects discovered more than one week before closest approach
 Rows highlighted blue indicate objects discovered more than one year before closest approach, i.e. objects successfully cataloged on a previous orbit, rather than being detected during final approach.
A notable case is the relatively large asteroid Duende, which was predicted nearly a year in advance, coincidentally approaching just a few hours after the unrelated Chelyabinsk meteor, which was unpredicted, but injured thousands of people when it impacted.
Largest per year.
From the lists in the first section, these are the largest-known asteroids per year that approach Earth within one LD. (More than one asteroid per year may be listed if its size is or more.) For comparison, the 1908 Tunguska event was caused by an object about in size, while the 2013 Chelyabinsk meteor which injured thousands of people and buildings when it generated a large airburst over Russia was estimated to be just across.
The table shows about 14 events in the 12 decades of 1900–2020 involving a body with an upper size estimate of or more making a close approach to Earth within one LD, with one (the Tunguska object) making impact.
The year 2011 was notable as two asteroids with size or more approached within one lunar distance.
Passed by outside of atmosphere.
Objects with distances greater than are listed here, although there is no discrete beginning of space.
Objects < 50 meters.
Asteroids smaller than about .
2020 QG—Closest asteroid flyby to not hit Earth, at , closest approach on 16 August 2020.
Objects > 50 meters.
Asteroids larger than about .
Predicted encounters.
Incomplete list of asteroids larger than about predicted to pass close to Earth (see also asteroid impact prediction and Sentry (monitoring system)):
A list of predicted NEO approaches at larger distances is maintained as a database by the NASA Near Earth Object Program.
Earth grazers.
Objects which enter and then leave Earth's atmosphere, the so-called 'Earth-grazers', are a distinct phenomenon, in as much as entering the lower atmosphere can constitute an impact event rather than a close pass. Earth grazer can also be short for a body that "grazes" the orbit of the Earth, in a different context.
External links.
E.A.R.N. — European Asteroid Research Node


Katherine Freese

Katherine Freese (born 8 February 1957) is a theoretical astrophysicist. She is currently a professor of physics at the University of Texas at Austin, where she holds the Jeff and Gail Kodosky Endowed Chair in Physics. She is known for her work in theoretical cosmology at the interface of particle physics and astrophysics.
Education and Academic Career.
Freese received her BA from Princeton University, one of the first women to major in physics at Princeton. She obtained her MA from Columbia University, and her PhD at the University of Chicago from advisor David Schramm. After postdoctoral fellowships at Harvard University, at the Kavli Institute for Theoretical Physics at University of California, Santa Barbara, and as a Presidential Fellow at the University of California, Berkeley, she became an Assistant Professor at MIT. She moved to the University of Michigan in Ann Arbor, where she was the George E. Uhlenbeck Professor of Physics. From 2007-2014 she was Associate Director of the Michigan Center for Theoretical Physics. In September 2014, she assumed the position of Director of Nordita, the Nordic Institute for Theoretical Physics, in Stockholm, and held a position as Visiting Professor of Physics at Stockholm University. In 2019, Freese moved to the University of Texas at Austin, where she holds the Jeff and Gail Kodosky Endowed Chair in Physics.
Contributions.
Freese has contributed to early research on dark matter and dark energy. She was one of the first to propose ways to discover dark matter. Her idea of indirect detection in the Earth is being pursued by the IceCube Neutrino Observatory experiment, and the "wind" of dark matter particles felt as the Earth orbits the Milky Way (work with David Spergel) is being searched for in worldwide experiments. Her work decisively ruled out MACHO (Massive compact halo object) dark matter in favor of WIMPs (weakly interacting massive particles). She has proposed a model known as "Cardassian expansion," in which dark energy is replaced with a modification of Einstein's equations. Recently she proposed a new theoretical type of star, called a dark star, powered by dark matter annihilation rather than fusion.
Freese has also worked on the beginnings of the universe, including the search for a successful inflationary theory to kick off the Big Bang. Her natural inflation model is a theoretically well-motivated variant of inflation; it uses axionic-type particles to provide the required flat potentials to drive the expansion. In 2013, observations made by the European Space Agency's Planck Satellite show that the framework of natural inflation matches the data. She has studied the Ultimate fate of the universe, including the fate of life in the universe."
Freese has served on the Board of the Kavli Institute for Theoretical Physics in Santa Barbara and the Board of the Aspen Center for Physics. From 2008-2012 she was a Councilor and Member of the Executive Committee of the American Physical Society, and from 2005-2008 she was a member of the Astronomy and Astrophysics Advisory Committee (AAAC). Currently she serves on the Board of the Oskar Klein Centre for Cosmoparticle Physics in Stockholm.
Honors.
Freese was elected Fellow of the American Physical Society in 2009. She received a Simons Foundation Fellowship in Theoretical Physics in 2012. In September 2012, Freese was awarded an Honorary Doctorate (Honoris Causa) from the University of Stockholm. She was awarded the 2019 Julius Edgar Lilienfeld Prize from the American Physical Society "For ground-breaking research at the interface of cosmology and particle physics, and her tireless efforts to communicate the excitement of physics to the general public."
In 2020 she was elected to the National Academy of Sciences.
Personal life.
Freese was born in Freiburg, Germany, to Ernst Freese and Elisabeth Bautz Freese. At age nine she emigrated to the United States. From her ten year marriage to Fred Adams she has a son, Douglas Quincy Adams. Her brother Andrew Freese, Chief of Neurosurgery at Brandywine Hospital, resides in Chester Springs, PA. Her uncle Ekkehard Bautz, now retired, was a molecular biologist and chair of the Institute of Molecular Genetics at the University of Heidelberg. Her cousin , a German actor, currently resides in Los Angeles.
Popular science.
Freese has written a review for the general educated public on dark matter and energy as they relate to recent research in cosmology and particle physics, titled "The Cosmic Cocktail: Three Parts Dark Matter" (Science Essentials, 2014, ). The book is partly autobiographical. She covers the contributions of Fritz Zwicky, for example, who was recently profiled as "the most important astronomer you've never heard of" and "the father of dark matter" on .


Michael Turner (cosmologist)

Michael S. Turner (born 29 July 1949) is a theoretical cosmologist, who coined the term "dark energy" in 1998.
He is the Bruce V. & Diana M. Rauner Distinguished Service Professor at the University of Chicago, and was formerly the Assistant Director for Mathematical and Physical Sciences for the US National Science Foundation from 2003–2006. His book "The Early Universe", co-written with fellow Chicago cosmologist Rocky Kolb and published in 1990, is a standard text on the subject.
Turner received a B.S. in Physics from the California Institute of Technology in 1971, and earned a PhD in Physics from Stanford University in 1978.
Turner helped establish the interdisciplinary field that combines together cosmology and elementary particle physics to understand the origin and evolution of the Universe. His research focuses on the earliest moments of creation, and he has made contributions to inflationary cosmology, particle dark matter and structure formation, the theory of big bang nucleosynthesis, and the nature of dark energy.
The National Academy study, "Connecting quarks with the cosmos: eleven science questions for the new century", which he chaired, identified opportunities at the intersection of Astronomy and Physics and has helped shape science investment in the US in this area.


Thomas Jacomb Hutton

Sir Thomas Jacomb Hutton, KCB, KCIE, MC & bar (27 March 1890 – 17 January 1981) was a British Army officer who held a variety of vital staff appointments between World War I and World War II, ultimately commanding the "Burma Army" during the early stages of the Japanese conquest of Burma in early 1942.
Hutton was married to Scottish psychiatrist Isabel Emslie Hutton (1887-1960).
Early life and First World War.
Thomas Jacomb Hutton was born on 27 March 1890 in Nottingham, Nottinghamshire, the eldest son of William Henry Hutton, and was educated at Rossall School and Royal Military Academy, Woolwich. On 23 December 1909, after passing out from Woolwich, he was, along with Edmond Schreiber, who like Hutton was a future general, commissioned as a second lieutenant into the Royal Artillery. Promoted on 23 December 1912 to lieutenant, Hutton served with the Royal Field Artillery on the Western Front throughout World War I, being promoted to captain in 1915 and brevet major in 1918. He became staff qualified, and served in 1918 as a General Staff Officer Grade 3 (GSO3) and as a brigade major from 1918 to 1919.
Between the wars.
From 1919 to 1920, Hutton served in the War Office as the Assistant Military Secretary and from 1923 to 1924 as the Deputy Assistant Adjutant General. He met Scottish psychiatrist Isabel Galloway Emslie (1887-1960) in Constantinople and they married in 1921.
After attending the Staff College, Camberley as a student from 1922 to 1923 from 1924 to 1926, Hutton was a General Staff Officer Grade 2 (GSO2) on the staff of Eastern Command, in the eastern counties of Britain. He was officially promoted to the full rank of Major in 1927, and from 1927 to 1930 he was the Military Assistant to the Chief of the Imperial General Staff (CIGS) and later attended the Imperial Defence College. He was "double jumped" to the rank of full colonel in 1930 and served from 1933 to 1936 as General Staff Officer Grade 1 (GSO1) in the Directorate of Military Operations in the War Office.
In 1936, Hutton served in the British forces in Palestine during the Arab revolt. From 1936 to 1938 he was the GSO1 (Chief of Staff) in the 1st Infantry Division (United Kingdom), which was sent to Palestine. He was promoted to major general and appointed General Officer Commanding (GOC) Western Independent District, in India.
World War II.
In 1940, after the outbreak of the Second World War, he was appointed Deputy Chief of the General Staff, GHQ India. The following year he was promoted Lieutenant General and appointed Chief of the General Staff in India.
Burma Army.
In 1942, Hutton was appointed General Officer Commanding Burma Command, which was facing imminent invasion by Japanese troops. Burma Army was subordinated to the American-British-Dutch-Australian Command, of which Wavell was Commander in Chief.
Hutton initially ordered his subordinates to fight as close to the borders as possible. Some of them thought that he was doing so on Wavell's orders, but Hutton actually wished to gain time for reinforcements to arrive. This resulted in the defeat of the ill-equipped and badly-trained Burmese and Indian formations which tried to fight close to the frontier.
Hutton now considered that Rangoon, the capital, could not be defended. He attempted to divert reinforcements to ports further north. Wavell considered this to be defeatism, and stormed at Hutton in front of witnesses at a meeting on 28 February. He did not argue back, feeling that a dignified silence was the best rebuke. Hutton had already been superseded by General Harold Alexander as GOC of Burma Army, and appointed Alexander's Chief of Staff, an embarrassing appointment he held until Burma Army was disbanded later in the year.
During the crisis in Burma in 1942, it was felt by some senior officers (such as General Sir Alan Hartley, the acting Commander in Chief in India), that Hutton made a good chief of staff but was not fitted for command in the field. In this respect, it was unfortunate that Hutton had held command of no major formation before being promoted to command an army.
Hutton subsequently served until 1944 as Secretary of the War Resources and Reconstruction Committees of Council, India. In 1944, he retired from the Army.
Later career.
Hutton held a variety of Civil Posts after his retirement: from 1944 to 1946, he was Officiating Secretary, Viceroy's Executive Council in India.
External links.


Charles Morse Huffer

Charles Morse Huffer (June 28, 1894 – March 9, 1981) was an American astronomer and instructor.
Biography.
He was born in Edinburgh, Indiana, the first son of Presbyterian minister Charles Huffer and his wife Nellie Morse. His grandfather, Frank Lyford Morse, was a Professor of Mathematics at Hanover College, and his father also had a strong interest in mathematics. Charles attended Albion College in Michigan, where he studied mathematics and graduated with an A.B. degree in 1916. Professor E. Roscoe Sleight at Albion arranged a graduate scholarship for Huffer to attend the University of Illinois.
While studying at the University of Illinois he attended an astronomy course taught by Joel Stebbins, the director of the University observatory. The class size was small and the two got to know each other, which would lead to future collaboration. The director of Lick Observatory, W. W. Campbell, wrote to Stebbins letting him know he needed a volunteer for a position at an observatory in Chile. Stebbins wrote back suggesting Huffer for the position, and, after the student graduated in 1917 with a Master of Arts in Mathematics, he accepted the opportunity.
In July 1917, Huffer left to join the University of California's D. O. Mills Expedition to the Southern Hemisphere at Santiago, Chile, where he assisted astronomer Ralph E. Wilson. When Wilson suddenly resigned in July 1918, Huffer was left to run the station for a year. While at Santiago, Huffer met the woman who would be his first wife, Ruth Triby from Indiana, a teacher for a local mission school for girls. They would have a daughter, Helen, in 1921.
During his time in Chile, Huffer's interest in astronomy grew, which would determine the path of his future career. After five years he returned to the States where he accepted a position as an assistant to Stebbins. As a graduate student, he taught a newly-formed undergraduate course on astronomy, while working as a photometrist for Stebbins at the Washburn Observatory. Not only was he noted to be a good observer, but he genuinely appeared to enjoy teaching. His first task was setting up the photometry equipment (that has been transferred from Illinois) on the school's 15 inch refractor telescope.
In his first year at Washburn, his pregnant wife died due to kidney failure, leaving him to raise their daughter alone. Huffer decided to focus himself on his work and studies. He received his Ph.D. in 1926 with a thesis titled, "Photo-Electric Studies of Four Variable Stars". This was the first doctorate in astronomy awarded by the University. Despite his career path, he retained an interest in mathematics. It was while auditing a class on complex variables in 1928 that he met Elizabeth Hart, who also held a Masters Degree in Mathematics. The two shared an interest in golf, and a game became their first date. The two were married, and would have sons John Charles, born 1929, and James Morse, born 1934.
Huffer spent the late 1920s measuring the variability of late type stars, particularly red giants. During the period 1933–41, Stebbins, Huffer, and Albert Whitford performed time-consuming research on the photometry of interstellar reddening. This involved measuring the colors of 1,332 B-type stars to determine how much their blue wavelengths became more attenuated with distance. A relationship was discovered between the position of the stars with respect to the Milky Way and the amount of reddening. Once the United States entered World War II, Huffer taught navigation to navy personnel and worked as a mathematician at the Badger Ordinance Depot. Despite this work, he continued to perform photoelectric measurements at the observatory, particularly on eclipsing binaries.
Following the war, he became secretary of the American Astronomical Society from 1946 until 1955. This involved much travel and planning for meetings. Stebbins retired from the University in 1948, and the same year Huffer became Full Professor. Huffer continued to teach at the University, and worked productively with one of his students, Olin J. Eggen, on several projects. In 1961, he retired from University of Wisconsin–Madison after 35 years at the institution, and was made professor emeritus.
In September 1961 he became professor at San Diego State College in California, were he remained until 1968, teaching and writing books. He worked with Frederick E. Trinklein of Racine College to write the first high school text on space science, titled "Modern Space Science", which was published in 1961. Huffer published a pocket-sized dictionary of astronomy called the "Astronomy Pocket Cramer" in 1963. In 1967 he was co-author of "An Introduction to Astronomy" with previous collaborator F. E. Trinklein plus Mark Bunge of San Jose City College. On his second retirement, he was also made professor emeritus. Most of his retirement was spent at Alpine, California, but prior to his death he moved back to Madison with his wife.
In 1973, Albion College presented him a Distinguished Alumni Award. A memorial sundial at Mount Laguna Observatory was named after him in 1992.


Liqiu

The traditional Chinese calendar divides a year into 24 solar terms. Lìqiū, "Risshū", "Ipchu", or "Lập thu" () is the 13th solar term. It begins when the Sun reaches the celestial longitude of 135° and ends when it reaches the longitude of 150°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 135°. In the Gregorian calendar, it usually begins around August 7 and ends around August 23.
Liqiu signifies the beginning of autumn in East Asian cultures.


Comet Machholz

Comet Machholz, formally designated C/2004 Q2, is a long-period comet discovered by Donald Machholz on August 27, 2004. It reached naked eye brightness in January 2005. Unusual for such a relatively bright comet, its perihelion was farther from the Sun than the Earth's orbit.
Period.
Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the aphelion distance (maximum distance) of this object. For objects at such high eccentricity, the Suns barycentric coordinates are more stable than heliocentric coordinates. Using JPL Horizons the barycentric orbital elements for epoch 2050 generate a semi-major axis of 537 AU and a period of approximately 12,400 years. This gives it a barycentric orbital period just a little larger than Sedna.
There are six other long-period comets named Machholz: C/1978 R3 (a.k.a. 1978 XIII, 1978l), C/1985 K1 (a.k.a. 1985 VIII, 1985e), C/1988 P1 (a.k.a. 1988 XV, 1988j), C/1992 N1 (a.k.a. 1992 XVII, 1992k), C/1994 T1 (a.k.a. 1994 XXVII, 1994r), and C/2010 F4. In addition, there are C/1992 F1 (Tanaka-Machholz), C/1994 N1 (Nakamura-Nishimura-Machholz) and C/2018 V1 (Machholz-Fujikawa-Iwamoto).


J. E. Talbot

John Ellis Talbot (24 April 1906 – 9 January 1967) was a British Building society manager, solicitor and Conservative Party politician.
Talbot was educated at Stubbington House School in Fareham and Rossall School in Fleetwood, Lancashire. He worked first as a solicitor; from 1938 he was Joint Manager of the Kidderminster Permanent Benefit Building Society. In 1936 he was elected as a Kidderminster councillor; after war service in the Royal Army Observer Corps (1941–1945), he was Mayor of the town from 1947 to 1949. He also served on Worcestershire County Council from 1952 to 1955.
He was elected as Member of Parliament (MP) for Brierley Hill, which was immediately to the north of Kidderminster, at the 1959 general election. In 1961 Talbot became Director and Chairman of the Kidderminster Equitable Building Society; he also followed his interest in gardening and became a Master of the Company of Gardeners (a London Livery company) in 1962. In 1964 he became Chairman of the Gardeners Royal Benevolent Society.
Brierley Hill was a marginal constituency and Talbot did well to keep it at the 1966 general election at which there was a swing to Labour. However, he died early the next year, at the age of 60.


Wonders of the Universe

Wonders of the Universe is a 2011 television series produced by the BBC, Discovery Channel, and Science Channel, hosted by physicist Professor Brian Cox. "Wonders of the Universe" was first broadcast in the United Kingdom on BBC Two from 6 March 2011. The series comprises four episodes, each of which focuses on an aspect of the universe and features a 'wonder' relevant to the theme. It follows on from Cox's 2010 series for the BBC, "Wonders of the Solar System". An accompanying book with the same title was also published.
Episodes.
1. "Destiny".
In the first episode, Cox considers the fundamental nature of time while pondering the ruins at Chankillo in Peru. He explores the familiarly brief cycles of time that define the lives of humans on Earth (such as days, months, and years), and compares them to the cycles of time on a cosmically universal scale (such as our solar system's 250 million year circuit around the Milky Way). At the Perito Moreno Glacier Cox introduces the Arrow of Time and the idea of irreversible change using GRB 090423 as an remnant of the early Stelliferous Era. At Kolmanskop he further discusses the thermodynamic arrow of time citing the inevitable increase of entropy, and stellar evolution. He continues by looking at Proxima Centauri, a slow burning red dwarf, and concludes the show over the Skeleton Coast of the Namib Desert, using the wreck of the "Eduard Bohlen" to illustrate the inevitable heat death of the universe.
2. "Stardust".
Cox travels to Kathmandu and visits the Pashupatinath Temple where he discusses the link between the stars and the elements of which all living things, including humans, are made. He explores the beginnings of the universe and the origins of humanity, going far back in time to look at the process of stellar evolution and comparing it to the formation cycle of the Himalayas. He describes 92 known elements found on Earth, which are mirrored in the spectrum observed through stellar classification. In northern Chile at El Tatio he compares the three states of water to the states found in the universe. He further explains how these basic elements are combined to form complexity through nuclear fusion. However, heavier elements than the first 26 only form when stars die and eject material during a supernova. In an abandoned prison in Rio de Janeiro Cox describes the dying stages of fusion, and in the 16-to-1 Mine he describes how the rarest and heaviest elements are made. In the Atacama Desert he concludes with the recycling of matter in the Universe and the possibility that the Earth was seeded with life from space.
3. "Falling".
This episode documents how gravity has a profound effect across the universe, and Cox seeks out a non-space zero-gravity experience to highlight his point. From the formation of galaxies and stars to the patterns of uplift and erosion seen on Earth, gravity is centrally important. Examples are given, such as the tidal force that captured and locked our moon over time, or more massively in the projected collision between the Andromeda and Milky Way Galaxies. Cox then enters a high-G training centrifuge to show how on Earth, gravity is a relatively weak force, but elsewhere in the Universe it is significantly stronger. In Chaco Culture National Historical Park he refers to Carl Sagan's Cosmos, and its link to a 3-week long supernova in 1054. The almost unimaginable crushing gravitational power of the Crab Pulsar is then contrasted to the distance of an atom's nucleus to its orbiting electrons. Finally, there is a look back at how Einstein's research on gravity has enabled us to better understand how gravity actually works within both "the falling valley" of spacetime and the "event horizon" of black holes.
4. "Messengers".
The final episode shows how the unique properties of visible light provide an insight into the origins and development of mankind and the Universe. At Karnak Temple in Egypt he observes the sunrise of the winter solstice through precisely aligned stone columns. The central star of the Lagoon Nebula, Herschel 36, and Eta Carinae are then compared to our sun, and the light from distant objects such as these allows us to engage on a journey back in time. Aboard a Hawker Hunter he easily breaks the sound barrier, but a speed of light was not first considered until the time of Ole Rømer in the 1670s. Cox then explains how the limitations of the light barrier allow scientists to measure distance and time with accuracy, and to peer back into the distant corners of the universe's creation. In 2003-2004 the Hubble Ultra-Deep Field captured images of galaxies 13 billion light-years distant, and a rainbow over the Victoria Falls in Zambia reveals a red-blue spectrum. The stretched "Invisible light" of the Big Bang is also discussed as part of the Cosmic microwave background as seen in the WMAP image. At Burgess Shale in Yoho National Park he concludes the series with the evolution of the eye and pikaia.
Rebroadcast.
The US broadcast was originally aired weekly from on 27 July to 17 August 2011, with the episodes re-titled as "Cosmos Made Conscious", "Children of the Stars", "The Known", and "On Beams of Light". The four episodes were repeated as part of the BBC Learning Zone (intended for use in Secondary Schools) in an early morning slot (5.00 - 6.00 am) on Wednesdays from the end of September 2011 on BBC Two. Each one-hour programme carried a subtitle ("Learning Shorts") and was segmented into 3 continuous short films (of approximately 20 minutes' duration) with separate titles, making 12 in total. The original episode titles were not used.
Reception.
The initial episode gained viewing figures of 6 million people when it was first shown on the BBC, and it was the first BBC factual show to top the iTunes chart. The series received generally positive reviews. Chris Harvey of the "Daily Telegraph" said "Cox is different. Scientists who can capture the popular imagination come along extremely rarely ... These days, science programmes regularly provide some of the most striking images ever seen on the small screen", and Tom Sutcliffe of "The Independent" commented "it's big on cosmic dazzlement and mind-boggling perspectives and full of epic orchestration and screen-saver graphics." Sam Wollaston of "The Guardian" chose to focus on Cox's presenting style rather than the scientific content of the programme.
Following complaints from viewers that the background music was loud enough to make Cox's narration difficult to hear, the BBC agreed to remix the sound for all the episodes. Cox thought this was a mistake, as he believed the series should be a "cinematic experience". The DVD and Blu-ray versions are released with the original sound mix as opposed to the broadcast versions.
Merchandise.
The accompanying hardcover book was released on 3 March 2011: A soundtrack album of music composed for "Wonders of the Universe" by Sheridan Tongue (including selected music from "Wonders of the Solar System") was released to coincide with the first airing of the show on BBC Two. The Region 1 DVD and Blu-ray discs were released on 30 August 2011. The Region 2 DVD and Blu-ray discs were released on 4 April 2011. The Region 4 DVD and Blu-ray discs were released on 1 September 2011.


List of people with craters of the Moon named after them

The following is a list of people whose names were given to craters of the Moon. The list of approved names in the "Gazetteer of Planetary Nomenclature" maintained by the International Astronomical Union includes the person the crater is named for.


Winer Observatory

Winer Observatory is an astronomical observatory near Sonoita, Arizona in the United States. It is a private, non-profit observatory, operated by Mark Trueblood since 1983. It has been the site of a number of significant small telescopes and famous robotic telescopes. It has been the site of the Iowa Robotic Observatory. The facility also hosted Michael Schwartz's telescope, active in supernova patrols, until Tenagra Observatories opened a facility in the area. Is the site of the Kilodegree Extremely Little Telescope.


David Flower

Professor David Flower is a British astronomer and physical chemist and the current Editor in Chief of the Monthly Notices of the Royal Astronomical Society (MNRAS). He is an Emeritus Professor in the Durham University Department of Physics. He became Editor in Chief after a long term as an MNRAS editorial board member. He is a Fellow of the Royal Astronomical Society, and a Fellow of the Royal Society of Arts.
The focus of Professor Flower's research is the physics and chemistry of the interstellar medium. Other research interests include atomic and molecular collision physics and astrophysics. He has authored a book entitled "Molecular Collisions in the Interstellar Medium" which was published in 2007 by Cambridge University Press of the United Kingdom. He has a long list of research published in peer review journals.


Theodore Meliteniotes

Theodore Meliteniotes (; Constantinople, c. 1320 - 8 March 1393) was a Byzantine Greek astronomer, a "sakellarios" (treasurer) in the Byzantine bureaucracy, a supporter of Gregory Palamas and an opponent of the reunion with the Catholic Church. He became "didaskalos ton didaskalon", i.e. the director of the Patriarchal School in 1360.
Works.
Theodore wrote an exegesis on the Gospels and a poem on Sôphrosynè (Temperance) which may be attributed to him.
Tribiblos.
Theodore's main work is his Astronomical "Tribiblos", in three books, whose autograph manuscript is preserved (Vaticanus gr. 792), was composed before 1352. The work deals with an assortment of mathematical and astronomical issues and draws from some earlier Greek authors like George Pachymeres and Theodore Metochites. The second book is devoted to Ptolemy, whose calculations he explained in the manner of Theon of Alexandria. Finally, in book 3 he devotes himself to Persian astronomy, drawing especially from George Chrysokokkes, whose work he corrected in many places. In all of them, he explicitly condemns Astrology, dissociating his Astronomy from the Persian tradition represented by Chrysokokkes.
The pedagogical character of the "Tribiblos" is obvious and it may have been used to give senior astronomy training to the Byzantine clergy.