(33342) 1998 WT24, Classification and orbit, Record close encounter
1998 WT24 is a potentially hazardous asteroid. That means its orbit takes it very close to Earth and if it were to collide with our planet, it would cause devastation on at least a regional scale. On 16 December 2001, it became the first PHA to be observed passing within 5 Lunar Distances (the average distance between Earth and the Moon) from Earth. Other asteroids have come closer, and numerous have even come closer than the Moon, but these have all been small asteroids, incapable of causing much damage to the planet, or much concern. The 2001 encounter was the closest known approach to Earth any PHA had made since (192642) 1999 RD32 passed by on 27 August 1969. However, 1999 RD32 was not discovered until September 1999 many years after its closest approach, so no one knew about 1999 RD32 in 1969.


(33342) 1998 WT24, Classification and orbit, Record close encounter
In September 2004, the well known PHA 4179 Toutatis came about 4 Lunar Distances from Earth. Due to its diameter being over ten times larger (5.7 km) and its closer approach, Toutatis at its closest (mag 8.9) was about half an apparent magnitude brighter than 1998 WT24 was at its closest (mag 9.5). However, Toutatis arrived during a full moon, and thus 1998 WT24's 2001 encounter is still the most easily observed flyby of an asteroid in history. It also made 1998 WT24 the first Near-Earth asteroid observed to be brighter than magnitude 10.


(33342) 1998 WT24, Classification and orbit, Frequent inner-planet encounters
1998 WT24 is a Mercury-crosser asteroid, a Venus-crosser asteroid, and an Earth-crosser asteroid. Because of its relatively low inclination (7.34°), it is able to come close to each of these planets. Its orbit takes it within 0.021 AU of Mercury's orbit, 0.0368 AU of Venus's orbit, and 0.00989 AU of Earth's orbit. It makes frequent encounters with these inner planets. The last time it came close to Mercury, Venus and Earth was 2010, 1977, and 12 November 2004, respectively.


(33342) 1998 WT24, Classification and orbit, Frequent inner-planet encounters
The most recent close approach to Earth was on 11 December 2015 at about 4.2 million kilometers (2.6 million miles, 11 lunar distances). The next visit of the asteroid to Earth's neighborhood will be on 11 November 2018, when it will make a relatively distant pass at about 20 million kilometers (12.5 million miles, 52 lunar distances). These encounters perturb its orbit parameters slightly, and each pass reduces its inclination further.


(33342) 1998 WT24, Physical characteristics
During its close encounters in 2001 and 2015, astronomers were able to make radar images of its surface and determine physical properties that remain unknown for most asteroids. According to the ExploreNEOs Warm Spitzer Exploration Science program, 1998 WT24 is a bright E-type asteroid with an exceptionally high albedo of 0.75±0.35.


(33342) 1998 WT24, Physical characteristics, Diameter and albedo
1998 WT24 measures between 350 and 415 meters in diameter and its surface has an albedo between 0.34 and 0.75. The Collaborative Asteroid Lightcurve Link an albedo of 0.34 and takes a diameter of 410 meters based on an absolute magnitude of 18.69. The asteroid is modestly elongated, approximately 420 × 330 meters.


(33342) 1998 WT24, Physical characteristics, Rotation period
Several rotational lightcurves of 1998 WT24 have been obtained from radiometric and photometric observations. Lightcurve analysis gave a consolidated rotation period of 3.697 hours with a brightness amplitude between 0.19 and 0.65 magnitude (U=3).


(33342) 1998 WT24, Future flyby candidate
1998 WT24 has an orbit that not only crosses Earth's orbit, but is roughly parallel to it at its furthest. This means that during favourable years it is easy to reach from Earth. Several times this decade, it will be an easier target than Earth's own Moon. It is high on the list of possible Near-Earth Asteroid targets for future flybys, landings, mining, or orbit manipulations.


(33342) 1998 WT24, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 28 January 2002. As of 2018, it has not been named.


(336756) 2010 NV1
(336756) 2010 NV1, prov. designation: 2010 NV1, is a highly eccentric planet crossing trans-Neptunian object, also classified as centaur and damocloid, approximately 52 kilometers (32 miles) in diameter. It is on a retrograde cometary orbit. It has a barycentric semi-major axis (average distance from the Sun) of approximately 286 AU.


(336756) 2010 NV1, Discovery
This trans-Neptunian object was discovered on 1 July 2010, by NASA's space-based Wide-field Infrared Survey Explorer (WISE). It was first observed by the Mount Lemmon Survey in 2009, extending the body's observation arc by 8 months prior to its official discovery observation by WISE.


(336756) 2010 NV1, Orbit and classification
2010 NV1 orbits the Sun at a distance of 9.4–547.2 AU once every 4643 years and 5 months (1,696,004 days; semi-major axis of 278.33 AU). Its orbit has an eccentricity of 0.97 and an inclination of 141° with respect to the ecliptic. It came to perihelion in December 2010 at a distance of 9.4 AU from the Sun. As of 2021, it is 21.3 AU from the Sun. It will not be 50 AU from the Sun until late 2044. After leaving the planetary region of the Solar System, 2010 NV1 will have a barycentric aphelion of 563 AU with an orbital period of 4830 years. In a 10 million year integration of the orbit, the nominal (best-fit) orbit and both 3-sigma clones remain outside 7.7AU (qmin) from the Sun.


(336756) 2010 NV1, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 31 August 2012 (M.P.C. 80287). As of 2021, it has not been named.


(336756) 2010 NV1, Physical characteristics
According to the surveys carried out by the NEOWISE mission, 2010 NV1 measures 44.2 kilometers in diameter and its surface has a low albedo of 0.057. More recent published data gives an diameter of 52.2±4.5 kilometers with an albedo of 0.042.


(341843) 2008 EV5
(341843) 2008 EV5, provisional designation 2008 EV5, is a sub-kilometer asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Aten group, approximately 400 metres (1,300 feet) in diameter. It was discovered on 4 March 2008, by astronomers of the Mount Lemmon Survey at Mount Lemmon Observatory near Tucson, Arizona, United States.


(341843) 2008 EV5, Origin and orbital history
2008 EV5 started its existence as part of a much larger body in the asteroid belt, with a likely diameter greater than 100 kilometers. 2008 EV5's immediate history likely started when its parent body experienced a large cratering event or, more likely, a catastrophic disruption event that resulted in a highly fractured, shattered, or reaccumulated object (rubble pile). As a result, 2008 EV5 may have been produced as a reassembly of ejected fragments. The location of what is now 2008 EV5 within this parent body is unknown.


(341843) 2008 EV5, Origin and orbital history
Given the available modeling work and data, the most plausible source family candidates for 2008 EV5 are Eulalia, New Polana, and Erigone. This assumes that 2008 EV5's true albedo is considerably lower than 10%. If it does have a high albedo, a plausible source would be a population of high-albedo C-type asteroids in the inner asteroid belt. Second tier candidate families for the high-albedo case are Baptistina and Pallas.


(341843) 2008 EV5, Origin and orbital history
From here, the newly liberated 2008 EV5 began to change via the forces referred to as the Yarkovsky and YORP effects. The Yarkovsky effect describes a small force that affects orbital motion. It is caused by sunlight; when objects heat up in the Sun, they reradiate the energy away as heat, which in turn creates a tiny thrust. This recoil acceleration is much weaker than solar and planetary gravitational forces, but it can produce substantial orbital changes over timescales ranging from many millions to billions of years. The same physical phenomenon also creates a thermal torque that probably caused 2008 EV5 to take on a top-like appearance.


(341843) 2008 EV5, Origin and orbital history
Dynamical models indicate that 2008 EV5 migrated inward across the inner asteroid belt over long timescales (i.e. the order of ~0.01–1 Gyr) until it reached a planetary gravitational resonance that drove it into the near-Earth asteroid (NEA) population over a timescale of the order of ~1 Myr. From there, gravitational interactions with both the planets and resonances allowed it to reach its current orbit within a few Myr to a few tens of Myr.


(341843) 2008 EV5, 2008 close approach
On 23 December 2008, 2008 EV5 made a close approach to Earth at a distance of 8.4 lunar distances (0.022 AU, 3.2 million km), its closest until 2169. Its brightness peaked on 26 December about 13.2 magnitude.


(341843) 2008 EV5, Physical characteristics
2008 EV5 is an oblate spheroid (also described as "muffin-shaped")400 m (1,300 ft) in diameter. It rotates very slowly in a retrograde direction. There is a 150 m (490 ft) diameter concave feature, possibly an impact crater, or a relic feature from a previous episode of rapid rotation that caused the asteroid's shape to reconfigure.


(341843) 2008 EV5, Physical characteristics
Visible and near-infrared spectroscopy show that 2008 EV5's composition is similar to that of carbonaceous chondrite meteorites.


(341843) 2008 EV5, Sample return mission
2008 EV5 was the preliminary baseline target of NASA's proposed sample-return Asteroid Redirect Mission. Besides 2008 EV5, several other asteroids, including Itokawa and Bennu, were considered for this mission, before its cancellation in 2017.


(342842) 2008 YB3
(342842) 2008 YB3, provisional designation: 2008 YB3, is a sizable centaur and retrograde damocloid from the outer Solar System, approximately 67 kilometers (42 miles) in diameter. It was discovered on 18 December 2008, by astronomers with the Siding Spring Survey at the Siding Spring Observatory in Australia. The minor planet was numbered in 2012 and has since not been named.


(342842) 2008 YB3, Orbit and classification
2008 YB3 orbits the Sun at a distance of 6.5–16.7 AU once every 39 years and 5 months (14,399 days; semi-major axis of 11.58 AU). Its orbit has an eccentricity of 0.44 and an inclination of 105° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Siding Spring in December 2008.


(342842) 2008 YB3, Orbit and classification, Retrograde centaur and damocloid
2008 YB3 is a member of the centaurs, a population of inward-moving bodies transiting from the Kuiper belt to the group of Jupiter-family comets. Orbiting mainly between Jupiter and Neptune, they typically have a semi-major axis of 5.5 to 30.1 AU. Centaurs are cometary-like bodies with an eccentric orbit. Their short dynamical lifetime is due to the perturbing forces exerted on them by the outer planets of the Solar System.


(342842) 2008 YB3, Orbit and classification, Retrograde centaur and damocloid
The object is on a retrograde orbit as it has an inclination of more than 90°. There are only about a hundred known retrograde minor planets out of nearly 800,000 observed bodies, and, together with 2013 LU28 and 2011 MM4, it is among the largest such objects. The object also meets the orbital definition for being a damocloid. This is a small group of cometary-like objects without a coma or tail and a Tisserand's parameter with respect to Jupiter of less than 2 besides a retrograde orbit.


(342842) 2008 YB3, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 29 October 2012, receiving the number (342842) in the minor planet catalog  (M.P.C. 80959). As of 2021, it has not been named. According to the established naming conventions, it will be named after one of the many centaurs from Greek mythology, which are creatures with the upper body of a human and the lower body and legs of a horse.


(342842) 2008 YB3, Physical characteristics
2008 YB3 has an intermediate BR color, in between the BB ("grey-blue") and RR ("very red") color classes. Sheppard's obtained color indices: B–I (1.750), B–R (1.260), R–I (0.490) and V–R (0.460) agree with most other centaurs. The resulting B–V index is 0.8 (subtracting V–R from B–R).


(342842) 2008 YB3, Physical characteristics, Diameter and albedo
According to the survey of centaurs and scattered-disc objects carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2008 YB3 measures 67.1 kilometers (41.7 miles) in diameter and its surface has an albedo of 0.062, which makes it too small to be considered as a dwarf-planet candidate.


(342842) 2008 YB3, Physical characteristics, Rotation period
As of 2021, no rotational lightcurve of has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.


(350462) 1998 KG3
(350462) 1998 KG3, is a sub-kilometer asteroid and near-Earth object of the Amor group, that is on a low-eccentricity and low-inclination orbit between the orbits of Earth and Mars. It was discovered by the Spacewatch survey at Kitt Peak National Observatory on 22 May 1998.


(350462) 1998 KG3, Description
1998 KG3 is an Amor asteroid, because its perihelion is less than 1.3 AU and does not cross Earth's orbit. The asteroid measures approximately 100–240 meters in diameter.


(350462) 1998 KG3, Description
Its orbit is within a region of stability where bodies may survive for the age of the Solar System, and hence it may have formed near its current orbit.


(350462) 1998 KG3, Description
Between 1900 and 2200 its closest approach to Earth is more than 0.12 AU.


(35396) 1997 XF11
(35396) 1997 XF11, provisional designation 1997 XF11, is a kilometer-sized asteroid, classified as a near-Earth object, Mars-crosser and potentially hazardous asteroid of the Apollo group.


(35396) 1997 XF11, Description
Three months after its discovery on 6 December 1997 by James V. Scotti of the University of Arizona's Spacewatch Project, the asteroid was predicted to make an exceptionally close approach to Earth on 28 October 2028. Additional precovery observations of the asteroid from 1990 were quickly found that refined the orbit and it is now known the asteroid will pass the Earth on 26 October 2028, at a distance of 0.0062 AU (930,000 km; 580,000 mi), about 2.4 times the Earth–Moon distance. During the close approach, the asteroid should peak at about apparent magnitude 8.2, and will be visible in binoculars.


(35396) 1997 XF11, Description
1997 XF11 measures between 0.7 and 1.4 kilometers in diameter.


(35396) 1997 XF11, Description
This asteroid also regularly comes near the large asteroid Pallas.


(35396) 1997 XF11, Description, IAU Circular
On 11 March 1998, using a three-month observation arc, a faulty International Astronomical Union circular and press information sheet were put out that incorrectly concluded "that the asteroid was 'virtually certain' to pass within 80% of the distance to the Moon and stood a 'small...not entirely out of the question' possibility of hitting the Earth in 2028." But by 23 December 1997, it should have been clear that XF11 had no reasonable possibility of an Earth impact.


(35396) 1997 XF11, Description, IAU Circular
Within hours of the announcement, independent calculations by Paul Chodas, Don Yeomans, and Karri Muinonen had calculated that the probability of Earth impact was essentially zero, and vastly less than the probability of impact from as-yet-undiscovered asteroids. Chodas (1999) concurs with Marsden (1999) that there was about 1 chance in a hundred thousand that XF11 could have passed through a keyhole—that is, until the 1990 precovery observations eliminated such possibilities. During the October 2002 close approach, the asteroid was observed by the 70-meter Goldstone radar dish, further refining the orbit.


(35671) 1998 SN165
(35671) 1998 SN165, prov. designation: 1998 SN165, is a trans-Neptunian object from the Kuiper belt located in the outermost region of the Solar System. It was discovered on 23 September 1998, by American astronomer Arianna Gleason at the Kitt Peak National Observatory near Tucson, Arizona. The cold classical Kuiper belt object is a dwarf planet candidate, as it measures approximately 400 kilometers (250 miles) in diameter. It has a grey-blue color (BB) and a rotation period of 8.8 hours. As of 2021, it has not been named.


(35671) 1998 SN165, Orbit and classification
1998 SN165 orbits the Sun at a distance of 36.5–39.7 AU once every 234 years and 9 months (85,755 days; semi-major axis of 38.06 AU). Its orbit has an eccentricity of 0.04 and an inclination of 5° with respect to the ecliptic. As of 2021 the object is at 37.2 AU, approaching the Sun until 15 July 2065, when it will come to perihelion. The body's observation arc begins at Kitt Peak in September 1998, just eight nights prior to its official discovery observation.


(35671) 1998 SN165, Orbit and classification
As a cubewano, also known as classical Kuiper belt object, 1998 SN165 is located in between the resonant plutino and twotino populations and has a low-eccentricity orbit. It belongs to the cold population, distinct from the "stirred" hot population with inclinations higher than 5°. In a previous publication, the object was originally classified as a plutino.


(35671) 1998 SN165, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 27 February 2002 and received the number 35671 in the minor planet catalog (M.P.C. 44869). As of 2021, it has not been named. Acoording to the established naming conventions, it will receive a mythological or mythic name (not necessarily from Classical mythology), in particular one associated with creation.


(35671) 1998 SN165, Physical characteristics
1998 SN165 has a blue-grey color (BB), with various color indices measured, giving a difference between the blue and red filter magnitude (BR) of 1.123 and 1.13, respectively.


(35671) 1998 SN165, Physical characteristics, Rotation period
In February 2001, a rotational lightcurve of 1998 SN165 was obtained from photometric observations by Pedro Lacerda and Jane Luu. Lightcurve analysis gave an ambiguous rotation period of 8.84 hours with a brightness amplitude of 0.16 magnitude (U=2). An alternative period of 8.70 hours is also possible.


(35671) 1998 SN165, Physical characteristics, Diameter and albedo
According to observations by the space-based Herschel and Spitzer telescopes, 1998 SN165 measures between 393 and 460 kilometers and its surface has a low albedo between 0.043 and 0.060. While Johnston's Archive adopts a diameter of 393 kilometers, astronomer Michael Brown gives a radiometric diameter of 473 kilometers and lists this object as a "probable" dwarf planet (400–500 km), which is the category with the second lowest certainty in his 5-class taxonomic system. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and calculates a diameter of 334 kilometers based on an absolute magnitude of 5.5. A generic magnitude-to-diameter conversion with an albedo of 0.9 gives a diameter of 352 kilometers.


(357439) 2004 BL86
(357439) 2004 BL86 is a bright sub-kilometer asteroid and binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters (980 ft) in diameter. It was discovered on 30 January 2004 by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. Its 70-meter (200 ft) moon was discovered during the asteroid's close approach to the Earth in January 2015.


(357439) 2004 BL86, 2015 Earth approach
On 26 January 2015 at 16:20 UTC, 2004 BL86 passed 1,199,600 km (745,400 mi), or 3.1 lunar distances, from Earth. The asteroid briefly peaked around apparent magnitude 9 and was near the celestial equator. The asteroid was visible in telescopes with objectives of 100 mm (4 in) or larger; high-end binoculars under a dark sky may also have worked. Near closest approach the asteroid was moving about 2.5 degrees per hour (2.5 arcseconds per second). The asteroid came to opposition (furthest elongation in the sky from the Sun) on 27 January 2015 at 04:37 UTC. Around 5:00 UTC, the asteroid was near M44 (the Beehive Cluster).


(357439) 2004 BL86, 2015 Earth approach
The 26 January 2015 approach of 3.1 lunar distances was the closest approach of 2004 BL86 for at least the next 200 years. For comparison, 2015 TB145, about twice the size of 2004 BL86, passed 486,800 km (302,500 mi), or 1.3 lunar distances, from Earth on 31 October 2015.


(357439) 2004 BL86, Satellite
A minor-planet moon, provisionally designated S/2015 (357439) 1, was first detected by ground-based telescopes by Joe Pollock and Petr Pravec. Observations by the Goldstone Deep Space Communications Complex and Green Bank Telescope confirmed that it is a binary asteroid with a secondary roughly 70 meters (200 ft) across. The secondary is estimated to orbit at least 500 meters (1,600 ft) from the primary. About 16% of asteroids over 200 meters (660 ft) in diameter are thought to be binaries.


(357439) 2004 BL86, Numbering and naming
This minor planet was numbered on 27 March 2013 (M.P.C. 83151). As of 2020, it has not been named.


(357439) 2004 BL86, Gallery
Animation of 2004 BL86's orbit   Sun ·    Earth  ·   2004 BL86


(367789) 2011 AG5
(367789) 2011 AG5, provisional designation 2011 AG5, is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It has a diameter of about 140 meters (460 ft). It was removed from the Sentry Risk Table on 21 December 2012 and as such it now has a rating of 0 on the Torino Scale.


(367789) 2011 AG5, Description
2011 AG5 was discovered on 8 January 2011 by the Mount Lemmon Survey at an apparent magnitude of 19.6 using a 1.52-meter (60 in) reflecting telescope. Pan-STARRS precovery images from 8 November 2010 extended the observation arc to 317 days. Observations by the Gemini 8.2-metre (320 in) telescope at Mauna Kea recovered the asteroid on October 20, 21 and 27, 2012, and extended the observation arc to 719 days.


(367789) 2011 AG5, Description
The October 2012 observations have reduced the orbit uncertainties by more than a factor of 60, meaning that the Earth's position in February 2040 no longer falls within the range of possible future paths for the asteroid. On 4 February 2040 the asteroid will pass no closer than 0.0066 AU (990,000 km; 610,000 mi) (~2.6 LD) from Earth. Until 21 December 2012 it was listed on the Sentry Risk Table with a rating on the Torino Scale of Level 1.


(367789) 2011 AG5, Description
A Torino rating of 1 is a routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. It is estimated that an impact would produce the equivalent of 100 megatons of TNT, roughly twice that of the most powerful nuclear weapon ever detonated (Tsar Bomba). This is powerful enough to damage a region at least a hundred miles wide.


(367789) 2011 AG5, Description, Older risks
Virtual clones of the asteroid that fit the mid-2012 uncertainty region in the known trajectory showed four potential impacts between 2040 and 2047. It had a 1 in 500 chance of impacting the Earth on 5 February 2040. In September 2013, there was an opportunity to make additional observations of 2011 AG5 when it came within 0.98 AU (147,000,000 km; 91,000,000 mi) of Earth. The 2013 observations allowed a further refinement to the known trajectory. The asteroid will also pass 0.0121 AU (1,810,000 km; 1,120,000 mi) from the Earth on 3 February 2023.


(367789) 2011 AG5, Description, Older risks
The 2023 gravitational keyhole was 227 miles (365 kilometers) wide. With a Palermo Technical Scale of -1.00, the odds of impact by 2011 AG5 were about 10 times less than the background hazard level of Earth impacts which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact.


(369623) 2011 DY5
(369623) 2011 DY5, provisional designation 2011 DY5, is a Tirela asteroid from the outer regions of the asteroid belt, approximately 3.2 kilometers (2.0 miles) in diameter. It was discovered on 30 August 2008, by French amateur astronomers Christophe Demeautis and Jean-Marie Lopez at the Pises Observatory in southern France.


(369623) 2011 DY5, Orbit and classification
2011 DY5 is a member of the Tirela family, a large asteroid family, also known as the Klumpkea family, named after the largest members 1040 Klumpkea and 1400 Tirela. The family consists of more than a thousand members and may be further divided into 8 different parts.


(369623) 2011 DY5, Orbit and classification
It orbits the Sun in the outer asteroid belt at a distance of 2.6–3.6 AU once every 5 years and 6 months (2,009 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.16 and an inclination of 18° with respect to the ecliptic. The body's observation arc begins with its official discovery observation as 2008 QZ41 at Pises in August 2008.


(369623) 2011 DY5, Physical characteristics
Based on a generic magnitude-to-diameter conversion, 2011 DY5 measures 3.2 kilometers in diameter for an absolute magnitude of 16.0 and an assumed albedo of 0.07, which is a typical value for a Tirela asteroid. As of 2018, no rotational lightcurve has been obtained from photometric observations. The asteroid's rotation period, poles and shape remain unknown.


(369623) 2011 DY5, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 21 August 2013 (M.P.C. 84643). As of 2018, it has not been named.


(374158) 2004 UL
(374158) 2004 UL is a sub-kilometer asteroid on an outstandingly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. The object is known for having the second-smallest perihelion of any known asteroid, after (137924) 2000 BD19.


(374158) 2004 UL
It was discovered on 18 October 2004 by the Lincoln Near-Earth Asteroid Research (LINEAR) at Lincoln Lab's ETS near Socorro, New Mexico.


(374158) 2004 UL, Orbit and classification
This Apollo asteroid orbits the Sun at a distance of 0.09–2.44 AU once every 17 months (521 days; semi-major axis of 1.27 AU). Its orbit has an outstandingly high eccentricity of 0.93 and an inclination of 24° with respect to the ecliptic.


(374158) 2004 UL, Orbit and classification
Due to its orbit, it is also a Mercury-crosser, Venus-crosser and Mars-crosser. It has an Earth minimum orbital intersection distance of 0.0182 AU (2,720,000 km), which translates into 7.1 lunar distances.


(374158) 2004 UL, Physical characteristics
In October 2014, a rotational lightcurve for this asteroid was obtained from photometric observations by American astronomer Brian Warner at the CS3–Palmer Divide Station (U82) in Landers, California. It gave a longer-than average rotation period of 38±2 hours (most minor planets take 2–20 hours to complete a full rotation) with a high brightness variation of 1.2 magnitude, indicating a non-spheroidal shape (U=2).


(374158) 2004 UL, Physical characteristics
Based on a generic magnitude-to-diameter conversion, 2004 UL measures between 0.5 and 1.2 kilometers. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 0.516 kilometers with an absolute magnitude of 18.8.


(374158) 2004 UL, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 18 October 2013 (M.P.C. 85347). As of 2018, it has not been named.


(38063) 1999 FH
(38063) 1999 FH is a rare-type asteroid from the inner regions of the asteroid belt, classified as Mars-crosser and exceptionally slow rotator, approximately 4 kilometers in diameter. It was discovered on 16 March 1999, by Croatian astronomers Korado Korlević and Mario Jurić at Višnjan Observatory in Croatia.


(38063) 1999 FH, Orbit and classification
1999 FH orbits the Sun at a distance of 1.7–3.0 AU once every 3 years and 7 months (1,309 days). Its orbit has an eccentricity of 0.29 and an inclination of 12° with respect to the ecliptic. A first precovery was taken at Steward Observatory in 1992, extending the body's observation arc by 7 years prior to its official discovery observation.


(38063) 1999 FH, Physical characteristics
SDSS photometry characterized 1999 FH as a rare and reddish L-type, which belong to the larger complex of stony asteroids.


(38063) 1999 FH, Physical characteristics, Slow rotator and tumbler
In September 2014, American astronomer Robert Stephens obtained a rotational lightcurve from photometric observations taken at the Center for Solar System Studies (CS3, U81) in California. It gave an exceptionally long rotation period of 990±50 hours with a brightness amplitude of 0.55 magnitude (U=2), which makes it one of the slowest rotators known to exist. It is also a suspected tumbling asteroid, which show a non-principal axis rotation.


(38063) 1999 FH, Physical characteristics, Diameter and albedo
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, 1999 FH measures 3.395 and 4.17 kilometers in diameter and its surface has an albedo of 0.287 and 0.176, respectively. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 3.92 kilometers with an absolute magnitude of 14.4.


(38063) 1999 FH, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 28 March 2002. As of 2018, it has not been named.


(385185) 1993 RO
This is the current revision of this page, as edited by UnaToFiAN-1 (talk | contribs) at 20:32, 27 December 2019 (copyedit). The present address (URL) is a permanent link to this version.


(385185) 1993 RO
(385185) 1993 RO is a plutino. It was the first plutino discovered after Pluto itself, with 1993 RP and (15788) 1993 SB a day and two days later, respectively. The discovery was made in 1993 at the Mauna Kea Observatory with a 2.2-meter telescope. Very little is known about (385185) 1993 RO. Even the diameter estimate of ~90 km is based on the assumed albedo of 0.09.


(385185) 1993 RO
KBO's found in 1993 include: (15788) 1993 SB, (15789) 1993 SC, (181708) 1993 FW, and (385185) 1993 RO.


(385250) 2001 DH47
(385250) 2001 DH47, provisional designation 2001 DH47, is a sub-kilometer asteroid and Mars trojan orbiting 60° behind the orbit of Mars near the L5 point.


(385250) 2001 DH47, Discovery, orbit and physical properties
2001 DH47 was discovered on 1 February 2001 by the Spacewatch program, observing from Steward Observatory, Kitt Peak and classified as Mars-crosser by the Minor Planet Center. Its orbit is characterized by low eccentricity (0.035), moderate inclination (24.4º) and a semi-major axis of 1.52 AU. Its orbit is well determined as it is currently (March 2013) based on 45 observations with a data-arc span of 3,148 days. It has an absolute magnitude of 19.7 which gives a characteristic diameter of 562 m.


(385250) 2001 DH47, Mars trojan and orbital evolution
It was identified as Mars trojan by H. Scholl, F. Marzari and P. Tricarico in 2005 and its dynamical half-lifetime was found to be of the order of the age of the Solar System. Recent calculations confirm that it is indeed a stable L5 Mars trojan with a libration period of 1365 yr and an amplitude of 11°. These values as well as its short-term orbital evolution are very similar to those of 5261 Eureka.


(385250) 2001 DH47, Origin
Long-term numerical integrations show that its orbit is very stable on Gyr time-scales (1 Gyr = 1 billion years). As in the case of Eureka, calculations in both directions of time (4.5 Gyr into the past and 4.5 Gyr into the future) indicate that 2001 DH47 may be a primordial object, perhaps a survivor of the planetesimal population that formed in the terrestrial planets region early in the history of the Solar System.


(385343) 2002 LV
(385343) 2002 LV, provisional designation 2002 LV, is a stony asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.5 kilometers (0.9 miles) in diameter. It was discovered on 1 June 2002, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. The Sr-type asteroid has a rotation period of 6.2 hours and is likely elongated.


(385343) 2002 LV, Orbit and classification
2002 LV is a member of the Earth-crossing group of Apollo asteroids, the largest group of near-Earth objects with approximately 10 thousand known members.


(385343) 2002 LV, Orbit and classification
It orbits the Sun at a distance of 0.9–3.7 AU once every 3 years and 6 months (1,286 days; semi-major axis of 2.31 AU). Its orbit has an eccentricity of 0.61 and an inclination of 30° with respect to the ecliptic. Due to its large aphelion, it also crosses the orbit of Mars at 1.66 AU. The body's observation arc begins with its official discovery observation at Socorro in June 2002.


(385343) 2002 LV, Orbit and classification, Close approaches
The asteroid has an Earth minimum orbital intersection distance of 0.0071 AU (1,060,000 km; 660,000 mi), which corresponds to 2.7 lunar distances and makes it a potentially hazardous asteroid due to its notably large size. In August 1935, it approached Earth at a nominal distance of 0.035 AU (14 LD), and in July 2002 at 0.112 AU (44 LD). Its closest near-Earth encounter is predicted to occur on 4 August 2076 at a distance of 0.0108 AU (4.2 LD) only (see table).


(385343) 2002 LV, Physical characteristics
Observations with the Spitzer Telescope characterized this object as an Sr-subtype that transitions from the common, stony S-type asteroids to the uncommon R-types.


(385343) 2002 LV, Physical characteristics, Rotation period
In July 2002, a rotational lightcurve of this asteroid was obtained from photometric observations by Petr Pravec at Ondřejov Observatory in the Czech Republic. Lightcurve analysis gave a well-defined rotation period of 6.195 hours with a high brightness amplitude of 0.93 magnitude, indicative for an elongated, non-spherical shape (U=3). The result agrees with a period of 6.2 hours measured at the Table Mountain Observatory and at the CS3-Palmer Divide Station (U82) in 2009 and 2016, respectively (U=2+/3-).


(385343) 2002 LV, Physical characteristics, Diameter and albedo
According to post-cryogenic observations with the Spitzer Telescope during the ExploreNEOs survey, and observations carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, this asteroid measures between 1.359 and 1.73 kilometers in diameter and its surface has an albedo between 0.15 and 0.2158. The Collaborative Asteroid Lightcurve Link assumes a stony standard albedo of 0.20 and calculates a diameter of 1.42 kilometers based on an absolute magnitude of 16.6.


(385343) 2002 LV, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 14 February 2014 (M.P.C. 87072). As of 2018, it has not been named.


(386454) 2008 XM
(386454) 2008 XM is a highly eccentric, sub-kilometer-sized asteroid, with one of the smallest known perihelions among all minor planets. It is classified as near-Earth object of the Apollo group and was discovered on 2 December 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States.


(386454) 2008 XM, Orbit and classification
The asteroid orbits the Sun at a distance of 0.1–2.3 AU once every 16 months (494 days). Its orbit has an eccentricity of 0.91 and an inclination of 5° with respect to the ecliptic. Due to its outstanding eccentricity, it is also a Mercury-crosser, Venus-crosser and Mars-crosser.


(386454) 2008 XM, Orbit and classification
It has the third-smallest perihelion of any numbered asteroid behind (137924) 2000 BD19 and (374158) 2004 UL. Its Earth minimum orbital intersection distance of 0.0047 AU (700,000 km) corresponds to only 1.9 lunar distances.


(386454) 2008 XM, Physical characteristics
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 367±9 meters in diameter and its surface has an albedo of 0.128. As of 2016, the body's composition and spectral type, as well as its rotation period and shape remains unknown.


(386723) 2009 YE7
(386723) 2009 YE7, provisional designation 2009 YE7, is a trans-Neptunian object (TNO) discovered by David Rabinowitz on December 17, 2009 at the La Silla Observatory in Chile.


(386723) 2009 YE7, Orbit, Classification
2009 YE7 is a classical Kuiper belt object: Its orbit is not controlled by an orbital resonance with Neptune, similar to 15760 Albion, but with a much greater orbital eccentricity and inclination. It completes one orbit around the Sun in just over 247 Earth years, at an average distance of about 44 AU. It came to perihelion around 1868, and to aphelion in 2015. It is currently about 50.7 AU from the Sun, and will again return to perihelion around 2163.


(386723) 2009 YE7, Orbit, Precovery
2009 YE7 has been observed 70 times, with precovery images dating back to 2006, and has an orbital quality code of 4.


(386723) 2009 YE7, Physical characteristics, Absolute magnitude
The size of an object can be ascertained once its absolute magnitude (H) and its albedo (the proportion of light it reflects) are known. When 2009 YE7 was first discovered, it was believed to have an absolute magnitude (H) of 2.8, which would have made it the first bright KBO found from the southern hemisphere. 2009 YE7 has an absolute magnitude (H) of 4.5. Since 2009 YE7 has an absolute magnitude dimmer than (H=1), it will not be overseen by two naming committees and will not automatically be listed as a dwarf planet by the International Astronomical Union (IAU).


(386723) 2009 YE7, Physical characteristics, Absolute magnitude
This value would've made it the eighth-intrinsically-brightest known trans-Neptunian object, but it was later found to be much dimmer. It has an absolute magnitude (H) of 4.5, which would make it a good dwarf-planet candidate when using an albedo of 0.09. However, it is probably much smaller than previously thought, since it is also suspected of being a highly reflective icy member of the Haumea family.


(386723) 2009 YE7, Physical characteristics, Absolute magnitude
2009 YE7 has been found to be a member of the Haumea family fragment due to its Haumea-like orbit and the detection of water ice on its surface. This means 2009 YE7 could have an albedo of up to 0.7, resulting in a small size close to 200 kilometres (120 mi). However, its actual albedo is unknown; if its albedo turns out to be lower, it would result in a larger size estimate.


(386723) 2009 YE7, Physical characteristics, Absolute magnitude
Any icy body with a diameter equal to or greater than 400 kilometres (250 mi) is expected to be spherical. Many small icy low-density moons, such as Mimas and Miranda are known to be spherical.


(388188) 2006 DP14
(388188) 2006 DP14, provisional designation 2006 DP14, is a sub-kilometer sized, peanut-shaped asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. This contact binary was discovered on 23 February 2006, by astronomers of the LINEAR program at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. On 10 February 2014, it passed 6.25 lunar distances from Earth. The asteroid is approximately 400 meters in diameter and has a rotation period of 5.77 hours.


(388188) 2006 DP14, Classification and orbit
2006 DP14 is a member of the Apollo group, which are Earth-crossing asteroids and the largest group of near-Earth asteroids.


(388188) 2006 DP14, Classification and orbit
It orbits the Sun at a distance of 0.3–2.4 AU once every 19 months (583 days; semi-major axis of 1.37 AU). Its orbit has a high eccentricity of 0.78 and an inclination of 12° with respect to the ecliptic. As no precoveries were taken, the body's observation arc begins with its discovery observation in 2006.


(388188) 2006 DP14, Classification and orbit, Close approaches
The asteroid has an Earth minimum orbit intersection distance (MOID) of 2,440,000 km (0.0163 AU), which corresponds to 6.4 lunar distances (LD). On 10 February 2014, it passed Earth close to this theoretical minimum distance at 6.25 LD, or 2,400,000 km (0.016032 AU). This makes is a potentially hazardous asteroid (PHA), a body with a threatening close approach to the Earth, due to its low MOID and large size (absolute magnitude of 18.9). PHAs are defined as objects with an absolute magnitude of 22 or brighter – which generically corresponds to a diameter of approximately 140 meters – and a MOID that is smaller than 0.05 AU or 19.5 LD.


(388188) 2006 DP14, Physical characteristics
2006 DP14 is an assumed stony S-type asteroid. This asteroid is a typical contact binary, with two distinctive lobes on either end that appear to be in contact, giving it a peanut-like shape.


(388188) 2006 DP14, Physical characteristics, Diameter, shape and albedo
On the night of 11 February 2014, NASA scientists conducted a radar imaging session using the 70-meter dish at Goldstone Observatory. These observations, using delay-Doppler radar imaging, revealed a 400×200 meters sized body, while the Collaborative Asteroid Lightcurve Link calculates a diameter of almost 500 meters, based on an assumed standard albedo for stony asteroids of 0.20 and an absolute magnitude of 18.9.


(388188) 2006 DP14, Physical characteristics, Diameter, shape and albedo
Amateur and professional astronomers helped track 2006 DP14 in the preceding days, so they would know just where to point the large antenna.


(388188) 2006 DP14, Physical characteristics, Rotation period
Goldstone's radiometric observations also gave a rotation period of approximately 6 hours. Photometric follow-up observations led to two light-curves that gave a refined period of 5.77 and 5.78 hours with a high brightness variation of 1.05 and 0.9, respectively (U=3/3). Its high brightness amplitude is also indicative for its elongated shape.


(38984) 2000 UZ4
(38984) 2000 UZ4, provisional designation 2000 UZ4, is carbonaceous Zhongguo asteroid from the outermost regions of the asteroid belt, approximately 5 kilometers (3 miles) in diameter. It was discovered on 24 October 2000, by astronomers with Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. The likely elongated C-type asteroid has a rotation period of 19.20 hours.


(38984) 2000 UZ4, Orbit and classification
2000 UZ4 is a non-family asteroid from the main belt's background population, and a member of the small group of Zhongguo asteroids, located in the Hecuba gap and locked in a 2:1 mean-motion resonance with the gas giant Jupiter. Contrary to the nearby unstable Griqua group, the orbits of the Zhongguos are stable over half a billion years.


(38984) 2000 UZ4, Orbit and classification
It orbits the Sun in the outer main-belt at a distance of 2.5–4.1 AU once every 6.04 years (2,206 days; semi-major axis of 3.32 AU). Its orbit has an eccentricity of 0.24 and an inclination of 0° with respect to the ecliptic. The body's observation arc begins with a precovery taken by Spacewatch in February 1996, more than 4 years prior to its official discovery observation at Socorro.


(38984) 2000 UZ4, Physical characteristics
2000 UZ4 has been characterized as a carbonaceous C-type asteroid by Pan-STARRS' large-scale survey.


(38984) 2000 UZ4, Physical characteristics, Rotation period
In January 2014, a rotational lightcurve of this asteroid was obtained from photometric observations in the R-band by astronomers at the Intermediate Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 19.20 hours with a high brightness amplitude of 0.70 magnitude, indicative of an elongated shape (U=2).


(38984) 2000 UZ4, Physical characteristics, Diameter and albedo
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 4.87 kilometers based on an absolute magnitude of 15.29.


(38984) 2000 UZ4, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 28 March 2002, after its orbit had sufficiently been secured (M.P.C. 45198). As of 2018, it has not been named.


(391211) 2006 HZ51
(391211) 2006 HZ51 is a bright, sub-kilometer asteroid on an eccentric orbit, classified as a near-Earth object and a potentially hazardous asteroid of the Amor group. It was discovered on 27 April 2006, by astronomers of the Catalina Sky Survey conducted at Mount Lemmon Observatory, Arizona, United States. During preliminary observations, it was thought to have a small chance of impacting Earth in 2008. The asteroid measures approximately half a kilometer in diameter and has an exceptionally high albedo.


(391211) 2006 HZ51, Orbit and classification
2006 HZ51 is an Amor asteroid – a subgroup of near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it.


(391211) 2006 HZ51, Orbit and classification
It orbits the Sun at a distance of 1.04–2.75 AU once every 2 years and 7 months (955 days; semi-major axis of 1.90 AU). Its orbit has an eccentricity of 0.45 and an inclination of 12° with respect to the ecliptic. The body's observation arc begins with a precovery taken by NEAT at Palomar Observatory in October 2001. With an aphelion of 2.75 AU, and typical for members of the Amor group, this asteroid is also a Mars-crosser, crossing the orbit of the Red Planet at 1.666 AU.


(391211) 2006 HZ51, Orbit and classification, Close approaches
2006 HZ51 has a minimum orbital intersection distance (MOID) with Earth of 5,290,000 km (0.035385 AU), which translates into 13.8 lunar distances.


(391211) 2006 HZ51, Orbit and classification, Close approaches
This makes it a potentially hazardous asteroid, a body with a threatening close approach to the Earth, due to its low MOID and large size (absolute magnitude of 18.5). Such asteroids are defined to have an absolute magnitude of 22 or brighter – which generically corresponds to a diameter of approximately 140 meters – and a MOID that is smaller than 0.05 AU or 19.5 LD.


(391211) 2006 HZ51, Orbit and classification, Close approaches
Based on a short observation arc of only 1.1 days, it was originally thought to have a 1 in 6 million chance of hitting Earth on 21 June 2008. Further refinement of the orbit quickly eliminated the risk. The preliminary 2-day orbit solution on 28 April 2006 was at first thought to have a period of 7 years and a perihelion of approximately 1.1 AU (MPEC 2006-H58).


(391211) 2006 HZ51, Physical characteristics, Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2006 HZ51 measures 412 meters in diameter and its surface has an exceptionally high albedo of 0.415. Other source give an estimated diameter of 800 meters.


(391211) 2006 HZ51, Physical characteristics, Rotation period
As of 2018, n rotational lightcurve of 2006 HZ51 has been obtained from photometric observations. The body's rotation period, pole and shape remains unknown.


(392741) 2012 SQ31
(392741) 2012 SQ31, provisional designation 2012 SQ31, is a sub-kilometer Florian asteroid from the inner regions of the asteroid belt, approximately 700 meters (2,300 feet) in diameter. It was originally considered a trans-Neptunian object and lost minor planet during 2004–2012. The date of the official discovery was later set to 27 December 2009, and credited to astronomers of the Spacewatch program conducted at the Kitt Peak National Observatory near Tucson, Arizona, in the United States.


(392741) 2012 SQ31, Orbit and classification
2012 SQ31 a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt. It orbits the Sun in the inner asteroid belt at a distance of 1.9–2.6 AU once every 3 years and 5 months (1,242 days; semi-major axis of 2.26 AU). Its orbit has an eccentricity of 0.14 and an inclination of 4° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Haleakala-AMOS, Hawaii, in December 2005, four years prior to its official discovery observation.


(392741) 2012 SQ31, Orbit and classification, Trans-Neptunian object
On 11 August 2004, the asteroid was already observed as 2004 PR107 by astronomers at the Cerro Tololo Inter-American Observatory in Chile, but became a lost minor planet until 2012 due to a lack of follow-up observations. During this time, and with only two observations taken on the same day, it was thought to be a trans-Neptunian object with a semi-major axis of 46 AU. Michael Brown listed it as a likely a dwarf planet on his website with an estimated diameter of 555 kilometers based on an absolute magnitude of 4.6 and an assumed albedo of 0.09.


(392741) 2012 SQ31, Orbit and classification, Trans-Neptunian object
In 2009, the lost asteroid was observed again as 2009 YS20, but was not identified at the time as being related to 2004 PR107. In 2012, it was finally rediscovered under its principal designation, reclassified as a small main-belt asteroid, and numbered two years later (see below).


(392741) 2012 SQ31, Physical characteristics
2012 SQ31 has been characterized as a member of the Flora family, which are stony S-type asteroids with albedo typically around 0.24, corresponding to that of the family's parent body, 8 Flora. Based on a generic magnitude-to-diameter conversion, 2012 SQ31 measures 690 meters for an absolute magnitude of 18.0 and an assumed albedo of 0.24. As of 2018, no rotational lightcurve has been obtained from photometric observations. The asteroid's rotation period, poles and shape remain unknown.


(392741) 2012 SQ31, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 15 April 2014 (M.P.C. 87941). As of 2018, it has not been named.


(394130) 2006 HY51
(394130) 2006 HY51 is a near-Earth object of the Apollo asteroid group with a high orbital eccentricity, approximately 1.2 kilometers in diameter. It was discovered on 26 April 2006, by LINEAR at Lincoln Lab's ETS in Socorro, New Mexico, United States.


(394130) 2006 HY51, Orbit and classification
2006 HY51 orbits the Sun at a distance of 0.1–5.1 AU once every 4 years and 2 months (1,527 days). Its orbit has an eccentricity of 0.97 and an inclination of 33° with respect to the ecliptic.


(394130) 2006 HY51, Orbit and classification
It is the asteroid with the third-smallest known perihelion of any known object orbiting the Sun. Its extreme orbital eccentricity brings it within 0.081 AU of the Sun (26% of Mercury's perihelion) and as far as 5.118 AU from the Sun (making it a Jupiter-grazer). It has a minimum orbit intersection distance with Earth of 0.1064 AU (15,900,000 km), equivalent to 41.5 lunar distances.


(394130) 2006 HY51, Orbit and classification
The small bodies with even more eccentric orbits are likely to suffer a rotational breakup by the age comparable to that of the Solar System, although 2006 HY51 itself is not expected to break.


(394130) 2006 HY51, Physical characteristics
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, 2006 HY51 measures 1.218 kilometers in diameter and its surface has an albedo of 0.157. The asteroid's composition and shape, as well as its rotation period remain unknown. It has an absolute magnitude of 17.2.


(39546) 1992 DT5
(39546) 1992 DT5  is a dark Hoffmeister asteroid and exceptionally slow rotator from the central region of the asteroid belt, approximately 5.3 kilometers (3.3 miles) in diameter. The likely elongated C-type asteroid was discovered on 29 February 1992, by the Uppsala–ESO Survey of Asteroids and Comets at ESO's La Silla astronomical observatory site in northern Chile.


(39546) 1992 DT5, Orbit and classification
1992 DT5 is an attributed member of the very compact Hoffmeister family (519), which, based upon its low albedo, was most likely formed from the breakup of a 50–100 kilometer-sized, carbon-rich parent body within the past several hundred million years. The family consist of nearly 2000 known members and its namesake is the asteroid 1726 Hoffmeister.


(39546) 1992 DT5, Orbit and classification
It orbits the Sun in the central main-belt at a distance of 2.7–2.9 AU once every 4 years and 8 months (1,704 days; semi-major axis of 2.79 AU). Its orbit has an eccentricity of 0.02 and an inclination of 5° with respect to the ecliptic. The body's observation arc begins with its discovery observation at La Silla in February 1992.


(39546) 1992 DT5, Physical characteristics
1992 DT5 is an assumed carbonaceous C-type asteroid. The overall spectral type of the Hoffmeister family is that of an C- and F-type.


(39546) 1992 DT5, Physical characteristics, Rotation period
In September 2013, a rotational lightcurve for this asteroid was obtained from photometric observations in the R-band at the Palomar Transient Factory in California. It gave an exceptionally long rotation period of 1167 hours with an estimated error margin of ±100 hours. According to the Light Curve Data Base (LCDB), it is the 8th slowest rotating minor planet known to exist. Due to its high brightness amplitude of 0.80 magnitude, the body has a likely elongated shape (U=2).


(39546) 1992 DT5, Physical characteristics, Diameter and albedo
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 5.3 kilometers based on an absolute magnitude of 15.09.


(39546) 1992 DT5, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 26 May 2002 (M.P.C. 45660). As of 2018, it has not been named.


(3R,6E)-nerolidol synthase
(3R,6E)-nerolidol synthase (EC , terpene synthase 1) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((3R,6E)-nerolidol-forming) . This enzyme catalyses the following chemical reaction


(3R,6E)-nerolidol synthase
The enzyme catalyses a step in the formation of (3E)-4,8-dimethylnona-1,3,7-triene.


(3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase
In enzymology, a (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase (EC ) is an enzyme that catalyzes the chemical reaction


(3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase
Thus, the two substrates of this enzyme are (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate and NAD+, whereas its 3 products are 3,4-dihydroxybenzoate, CO2, and NADH.


(3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase
This enzyme is a part of the terephthalate degradation pathway in bacteria.


(3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase, Family
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate:NAD+ oxidoreductase. Another name in common use is (1R,2S)-dihydroxy-3,5-cyclohexadiene-1,4-dicarboxylate dehydrogenase. This enzyme employs one cofactor, iron.


(3S,6E)-nerolidol synthase
(3S,6E)-nerolidol synthase (EC , (E)-nerolidol synthase, nerolidol synthase, (3S)-(E)-nerolidol synthase, FaNES1) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((3S,6E)-nerolidol-forming) . This enzyme catalyses the following chemical reaction


(3S,6E)-nerolidol synthase
The enzyme catalyses a step in the formation of (3E)-4,8-dimethylnona-1,3,7-triene.


(4+3) cycloaddition
A (4+3) cycloaddition is a cycloaddition between a four-atom π-system and a three-atom π-system to form a seven-membered ring. Allyl or oxyallyl cations (propenylium-2-olate) are commonly used three-atom π-systems, while a diene (such as butadiene) plays the role of the four-atom π-system. It represents one of the relatively few synthetic methods available to form seven-membered rings stereoselectively in high yield.


(4+3) cycloaddition, Introduction
Symmetry-allowed (4+3) cycloaddition is an attractive method for the formation of historically difficult-to-access seven-membered rings. Neutral dienes and cationic allyl systems (most commonly oxyallyl cations) may react in a concerted or stepwise fashion to give seven-membered rings. A number of dienes have been employed in the reaction, although cyclic, electron-rich dienes such as those found in the cyclopentadiene and furan ring systems are the best 4π systems for this process. Intramolecular variants are also efficient.


(4+3) cycloaddition, Introduction
Recent developments have focused on expanding the scope of enantioselective (4+3) cycloadditions and the range of conditions available for generating the key oxyallyl cation (propenylium-2-olate) intermediate.


(4+3) cycloaddition, Mechanism and stereochemistry, Prevailing mechanism
Oxyallyl cations (propenyliumolates) may be generated under reductive, mildly basic, or photolytic conditions. Reduction of α,α'-dihalo ketones is a very popular method for generating symmetric oxyallyl cations. After formation of a metal enolate, dissociation of halide generates a positively charged oxyallyl intermediate. This electron-deficient 2π component reacts with electron-rich dienes to give cycloheptenones. Cyclic dienes fare better than the corresponding acyclic dienes because in order to react, the diene must be in the s-cis conformation in the presence of the short-lived oxyallyl cation—cyclic dienes are locked in this reactive conformation.


(4+3) cycloaddition, Mechanism and stereochemistry, Prevailing mechanism
Substituents at the 1 and 3 positions are usually required to stabilize the oxyallyl cation and prevent isomerization to cyclopropanones and allene oxides. In most cases, an excess of the diene is employed to prevent isomerization of the oxyallyl cation intermediate. Increasing the covalent character of the metal-oxygen bond (by, for instance, employing iron carbonyl reducing agents instead of sodium) also stabilizes the oxyallyl cation, leading to cleaner reactions. Strongly electrophilic allyl cations tend to give products of electrophilic substitution rather than cycloaddition.


(4+3) cycloaddition, Mechanism and stereochemistry, Prevailing mechanism
The cycloaddition itself may be either concerted or stepwise, depending on the nature of the oxyallyl intermediate and the reaction conditions. Concerted reactions taking place under reductive conditions usually exhibit low regioselectivity due to somewhat indiscriminate frontier orbital control; however, stepwise (or at least asynchronous) reactions under basic conditions do exhibit moderate regioselectivity (attributed to initial formation of a bond between the less sterically hindered ends of the pi systems).


(4+3) cycloaddition, Mechanism and stereochemistry, Stereochemistry
Stereochemical control in the (4+3) cycloaddition is not as strict as in the Diels-Alder reaction, because the former often proceed through stepwise, polar pathways. Even when the reaction is concerted, complications may arise due to conformational dynamics in the oxyallyl component, which can exist in "W," "U," or "sickle" forms. Generally, however, the "W" form dominates. Even so, two stereochemically distinct transition states are possible: a chair-like, "extended" TS which leads to a cis relationship between the bridging atom and oxyallyl substituents, and a boat-like, "compact" TS which leads to a trans relationship.


(4+3) cycloaddition, Mechanism and stereochemistry, Stereochemistry
Which transition state is favored depends on both the 4π and 2π reacting partners. Reactions of cyclic dienes tend to favor the compact over the extended TS (this is particularly true for furan). In addition, the electrophilicity of the oxyallyl cation is related to the favorability of the extended transition state—more electrophilic cations (which possess more covalent metal-oxygen bonds) tend to favor the extended transition state, while less electrophilic cations favor the compact transition state.


(4+3) cycloaddition, Scope and limitations
Reduction of α,α'-dihalo ketones is an effective method for the generation of oxyallyl cations for cycloaddition. Reducing agents used include copper-bronze., iron carbonyl complexes., and copper/zinc As mentioned previously, products exhibiting trans stereochemistry between the bridging atom and the oxyallyl substituents (resulting from the compact transition state) are generally favored.


(4+3) cycloaddition, Scope and limitations
α-Halo ketones with hydrogens at the α' position can also be transformed into oxyallyl cations under basic conditions. This usually requires highly polar media, and the use of a halophilic Lewis acid (such as Ag+) is sometimes necessary.


(4+3) cycloaddition, Scope and limitations
Photochemical routes to oxyallyl cations generally result in the formation of a new covalent bond before the cycloaddition itself takes place. These reactions thus may lead to the formation of three new carbon-carbon bonds in a single operation.


(4+3) cycloaddition, Scope and limitations
Intramolecular (4+3) cycloadditions are also possible, and often lead to interesting bridged architectures that are difficult to access by other methods. The product below, for instance, features a rare trans-bridging ketone.


(4+3) cycloaddition, Synthetic applications
A synthesis of Prelog-Djerassi lactone illustrates how stereocenters set during a (4+3) cyclization may be used later for stereochemical control. The oxabicyclo[3.2.1]octane products of cycloadditions involving furan may be opened using a variety of methods


(4+3) cycloaddition, Comparison with other methods
Compared to annulations that form five- and six-membered rings, annulations that form seven-membered rings are relatively rare. Classical methods of cyclising linear precursors by the formation of a single carbon-carbon bond (such as the Prins reaction, shown below) form seven-membered rings efficiently in some cases.


(4+3) cycloaddition, Comparison with other methods
Transition metal-catalyzed (5+2) cycloadditions of vinylcyclopropanes with 2π units are also useful for the formation of seven-membered rings.


(4+3) cycloaddition, Experimental conditions and procedure, Typical conditions
Cycloadditions carried out under reductive conditions can generally be effected with commercially available reducing agents, although a few reducing agents require special preparation. Reductive reactions employing iron carbonyl complexes should be carried out in a well-ventilated fume hood, as free carbon monoxide may be released. The optimal conditions for base-mediated cycloadditions vary somewhat, although polar media tend to give higher yields—fluorinated solvents are more effective than their non-fluorinated analogues, and alkoxide or amine bases work better than others.


(40314) 1999 KR16
(40314) 1999 KR16 is a trans-Neptunian object on an eccentric orbit in the outermost region of the Solar System, approximately 254 kilometers (158 miles) in diameter. It was discovered on 16 May 1999, by French astronomer Audrey Delsanti and Oliver Hainaut at ESO's La Silla Observatory in northern Chile. The very reddish object is a dwarf planet candidate and has a rotation period of 11.7 hours.


(40314) 1999 KR16, Orbit and classification
The minor planet orbits the Sun at a distance of 34–65 AU once every 346 years (126,383 days; semi-major axis of 49.29 AU). Its orbit has an eccentricity of 0.31 and an inclination of 25° with respect to the ecliptic.


(40314) 1999 KR16, Numbering and naming
This minor planet was numbered by the Minor Planet Center on 26 May 2002. As of 2019, it has not been named.


(40314) 1999 KR16, Physical characteristics
1999 KR16 has two solutions of its rotation period of 6 and 12 hours, respectively, and an albedo of 0.20.


(410777) 2009 FD
(410777) 2009 FD is a carbonaceous sub-kilometer asteroid and binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, discovered on 24 February 2009 by astronomers of the Spacewatch program at Kitt Peak National Observatory near Tucson, Arizona, in the United States.


(410777) 2009 FD
Until 2019, the asteroid's modelled orbit placed it at risk of a possible future collision with Earth in 2185. It had the third highest cumulative impact threat of all known asteroids on the Palermo Technical Impact Hazard Scale based on its estimated diameter of 160 meters, kinetic yield, impact probability, and time interval. Observations to 2019 have extended the observation arc by four years and detected a favourable Yarkovsky effect, which rules out impact in 2185. Using observations from 16 November 2020, the asteroid was removed from the Sentry risk table on 19 November 2020.


(410777) 2009 FD, Discovery
2009 FD was initially announced as discovered on 16 March 2009 by La Sagra Sky Survey. Because there were previous observations found in images taken by the Spacewatch survey some 3 weeks prior, on 24 February 2009, the Minor Planet Center assigned the discovery credit to Spacewatch under the discovery assignment rules. 2009 FD made a close pass to Earth on 27 March 2009 at a distance of 0.004172 AU (624,100 km; 387,800 mi) and another on 24 October 2010 at 0.0702 AU.


(410777) 2009 FD, Discovery
2009 FD was recovered at apparent magnitude 23 on 30 November 2013 by Cerro Paranal Observatory, several months before the close approach of April 2014 when it passed 0.1 AU from Earth. It brightened to roughly apparent magnitude 19.3 around mid-March 2014. One radar Doppler observation of 2009 FD was made in 2014. The October–November 2015 Earth approach was studied by the Goldstone Deep Space Network.


(410777) 2009 FD, Binary
NASA's Near Earth Program originally estimated its size to be 130 metres in diameter based on an assumed albedo of 0.15. This gave it an estimated mass of around 2,800,000 tonnes. But work by Amy Mainzer using NEOWISE data in 2014 showed that it could be as large as 472 metres with an albedo as low as 0.01. Because 2009 FD (K09F00D) was only detected in two (W1+W2) of the four wavelengths the suspected NEOWISE diameter is more of an upper limit. Radar observations in 2015 showed it to be a binary asteroid. The primary is 120–180 meters in diameter and the secondary is 60–120 meters in diameter.


(410777) 2009 FD, Future approaches
The JPL Small-Body Database shows that 2009 FD will make two very close approaches in the late 22nd century, in 2185 and 2190. As of 2016, the approach of 29 March 2185 had a 1 in 710 chance of impacting Earth. The nominal 2185 Earth approach distance was 0.009 AU (1,300,000 km; 840,000 mi). Orbit determination for 2190 is complicated by the 2185 close approach. The precise distance that it will pass from Earth and the Moon on 29 March 2185 will determine the 30 March 2190 distance. 2009 FD should pass closer to the Moon than Earth on 29 March 2185. An impact by 2009 FD would cause severe devastation to a large region or tsunamis of significant size.


(410777) 2009 FD, Future approaches, Past Earth-impact estimates
In January 2011, near-Earth asteroid 2009 FD (with observations through 7 December 2010) was listed on the JPL Sentry Risk Table with a 1 in 435 chance of impacting Earth on 29 March 2185. In 2014 (with observations through 5 February 2014, creating an observation arc of 1807 days) the potential 2185 impact was ruled out. Using the 2014 observations, the Yarkovsky effect has become more significant than the position uncertainties. The Yarkovsky effect has resulted in the 2185 virtual impactor returning. While 2009 FD was estimated to be 470 meters in diameter, it was rated −0.40 on the Palermo Scale, placing it higher on the Sentry Risk Table than any other known object at the time.


(410777) 2009 FD, Future approaches, Past Earth-impact estimates
On 14 June 2019, Alessio Del Vigna and colleagues published a new analysis, which incorporates astrometry taken in 2019. Using both JPL's Sentry as well as NEODyS's CLOMON-2 system, the new data allowed a 4-sigma detection of the Yarkovsky effect at (+3.6±0.9)×10−3 AU/Myr. The 2019 observations extended the observation arc from six years to ten years. This ruled out the 2185 impact possibility, leaving the potential impact in 2190 as the only theoretically possible impact until 2250, at a very low probability of 1 in 100 million. On 19 November 2020, the asteroid was finally completely removed from the sentry risk table as all possible impacts, including 2190 and 2250, were ruled out.


(415029) 2011 UL21
(415029) 2011 UL21, provisional designation 2011 UL21, is an Apollo class potentially hazardous asteroid discovered on October 17, 2011 by the Catalina Sky Survey project. The asteroid is estimated to have a diameter of 2.5 kilometres (1.6 mi). It was rated at Torino Scale 1 on October 27, 2011 with an observation arc of 9.6 days.


(415029) 2011 UL21, Description
2011 UL21 briefly had about a 1 in a million chance of impacting in 2029. Its cumulative impact probability dropped to 1 in 71 million by 2 November 2011 when the observation arc reached 15 days. It was removed from the Sentry Risk Table on 4 November 2011 when all impact scenarios for the next 100 years or more were ruled out. During 2029, the closest approach to Earth is 1.6 AU. Palomar Observatory precovery images from 1989 and 1990 have extended the observation arc to 22 years. Its next notable close approach to the Earth will be on June 27, 2024 at a distance of 0.044 AU (6,600,000 km; 4,100,000 mi).


(415029) 2011 UL21, Description
With an absolute magnitude of 15.8, it is one of the brightest and therefore largest potentially hazardous asteroids (PHA) detected since (242450) 2004 QY2. The next largest PHA (based on absolute magnitude) discovered in 2011 is 2011 WO41 with an absolute magnitude of 16.8.


(415713) 1998 XX2
(415713) 1998 XX2 is a sub-kilometer asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Aten group. It was discovered 8 December 1998, by the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site, and was found to have frequent approaches to the Earth, Venus, and Mercury.


(415713) 1998 XX2, Orbit
The orbit of 1998 XX2 is well-established, and appears on the list of PHA close approaches to Earth, with the next approach at a distance of 0.020237 AU (3,027,400 km; 1,881,100 mi) on 28 November 2028. During the years 1900–2200,  close approaches are 0.017 AU (2,500,000 km; 1,600,000 mi) of the Earth (on 30 Nov 1991), as close as 0.035 AU (5,200,000 km; 3,300,000 mi) of Venus (on 28 Jan 1902 and 8 April 2039), and as close as 0.029 AU (4,300,000 km; 2,700,000 mi) of Mercury on 12 occasions. For comparison, the distance to the Moon is about 0.0026 AU (384,400 km).


(415713) 1998 XX2, Orbit
From 1993 to 1998, 1993 DA was the asteroid with the lowest known aphelion at 1.023 AU, and was thus the closest thing to an Apohele asteroid known at the time. When (33342) 1998 WT24 was discovered 25 November 1998, it was found to have a slightly smaller aphelion (1.019 AU) than 1993 DA, so (33342) 1998 WT24 took the title. However, (33342) 1998 WT24 lost its smallest aphelion title almost immediately when (415713) 1998 XX2 (aphelion of 1.014 AU) was discovered only a few weeks later on 8 December 1998.


(415713) 1998 XX2, Orbit
The Jupiter Tisserand invariant, used to distinguish different kinds of orbits, is 7.7.


(416151) 2002 RQ25
(416151) 2002 RQ25 is a carbonaceous asteroid of the Apollo group, classified as near-Earth object and potentially hazardous asteroid, approximately 0.2 kilometers in diameter. It was discovered on 3 September 2002, by the Campo Imperatore Near-Earth Object Survey (CINEOS) at the Italian Campo Imperatore Observatory, located in the Abruzzo region, east of Rome.


(416151) 2002 RQ25, Orbit and classification
2002 RQ25 orbits the Sun at a distance of 0.8–1.5 AU once every 1 years and 2 months (428 days). Its orbit has an eccentricity of 0.31 and an inclination of 5° with respect to the ecliptic.


(416151) 2002 RQ25, Orbit and classification
The asteroid's minimum orbit intersection distance with Earth is 0.0499 AU (7,460,000 km), which is currently exactly at the threshold limit of 0.05 AU (or about 19.5 lunar distances) to make it a potentially hazardous object.


(416151) 2002 RQ25, Physical characteristics
The carbonaceous C-type asteroid is also classified as a C/X-type body according to the survey carried out by NASA's Spitzer Space Telescope.


(416151) 2002 RQ25, Lightcurve
A rotational lightcurve of 2002 RQ25 was obtained from photometric observations made by American astronomer Brian Warner at his Palmer Divide Observatory, Colorado, in February 2015. The ambiguous lightcurve rendered a rotation period of 12.191±0.005 hours with a brightness variation of 0.72 magnitude (U=2+), while a second solution gave 6.096 hours (or half of the first period) with an amplitude of 0.43.


(416151) 2002 RQ25, Lightcurve
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates diameter of 225 meters with an absolute magnitude of 20.6.


(416400) 2003 UZ117
(416400) 2003 UZ117 is a trans-Neptunian object and suspected member of the Haumea family, located in the Kuiper belt in the outermost region of the Solar System. It was discovered on 24 October 2003, by astronomers of the Spacewatch survey project at Kitt Peak Observatory, Arizona. The object may also be a non-resonant cubewano.


(416400) 2003 UZ117, Orbit and physical characterization
2003 UZ117 orbits the Sun at a distance of 38.3–49.8 AU once every 292 years and 5 months (semi-major axis of 44.05 AU). Its orbit has an eccentricity of 0.13 and an inclination of 27° with respect to the ecliptic. Precovery images have been identified back to 2002.


(416400) 2003 UZ117, Orbit and physical characterization
Estimates for its diameter range between 138 and 423 kilometers. Two rotational lightcurves of the object gave a rotation period of 6 and 10.61 hours with a brightness amplitude of 0.1 and 0.09 in magnitude, respectively (U=1/2). It has a spectral type of BB, with a grey/blue rather than red color.


(416400) 2003 UZ117, Origin
Based on their common pattern of infrared water-ice absorption and the clustering of their orbital elements, the other KBOs, it appear to be collisional fragments broken off the dwarf planet Haumea. The neutral color of the spectrum of these objects in the visible range evidences a lack of complex organics on the surface of these bodies that has been studied in detail for the surface of Haumea.


(417634) 2006 XG1
(417634) 2006 XG1 provisional designation 2006 XG1, is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, that had a low but non-zero probability of impacting Earth on 31 October 2041. The asteroid was discovered on 20 September 2006, by astronomers of the Catalina Sky Survey, using a dedicated 0.68-meter telescope at Mount Lemmon Observatory in Arizona, United States.


(417634) 2006 XG1, Description
Originally listed with a Torino Scale hazard rating of 0, this was raised to a rating of 1 on 22 December 2006 as a result of additional observations and refinement of the orbital calculations. However, on 9 January 2007 it was returned to a rating of 0. It was removed from the Sentry Risk Table on 7 February 2007.


(417634) 2006 XG1, Description
It is now known that the asteroid will not make a close approach to the Earth in 2041. On 31 October 2041, the asteroid will be 1.69 AU (253,000,000 km; 157,000,000 mi) from the Earth. 2006 XG1 passed 0.0298 AU (4,460,000 km; 2,770,000 mi) from asteroid 87 Sylvia on 20 June 1969. It is also a Mars-crosser asteroid.


(417634) 2006 XG1, Description, Physical characteristics
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2006 XG1 measures 418 meters in diameter and its surface has an albedo of 0.154. Previously, JPL's Sentry System estimated a diameter of 670 meters with a mass of 4.2×1011 kg.


(418993) 2009 MS9
(418993) 2009 MS9, provisionally known as 2009 MS9, is a centaur roughly 30–60 km in diameter. It has a highly inclined orbit and a barycentric semi-major axis (average distance from the Sun) of ~353 AU.


(418993) 2009 MS9
2009 MS9 has a well determined orbit and has been assigned a minor planet number. Objects such 2009 MS9 may be the origin of Halley-type comets.


(418993) 2009 MS9
It came to perihelion in February 2013 at a distance of 11 AU from the Sun (outside the orbit of Saturn). As of 2016, it is 12 AU from the Sun.


(418993) 2009 MS9
It will not be 50 AU from the Sun until 2047. After leaving the planetary region of the Solar System, 2009 MS9 will have a barycentric aphelion of 696 AU with an orbital period of 6640 years.


(418993) 2009 MS9
In a 10 million year integration of the orbit, the nominal (best-fit) orbit and both 3-sigma clones remain outside 8.3AU (qmin) from the Sun.


(419624) 2010 SO16
(419624) 2010 SO16 is a sub-kilometer asteroid in a co-orbital configuration with Earth, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered by the Wide-field Infrared Survey Explorer space telescope (WISE) on 17 September 2010.


(419624) 2010 SO16, Description
The orbit was described by  Apostolos Christou and David Asher at the Armagh Observatory in Northern Ireland. The object has an absolute magnitude of 20.5. Observations by the discovering WISE telescope give a diameter of 357 meters and an albedo of 0.084.


(419624) 2010 SO16, Description
2010 SO16 has a horseshoe orbit that allows it to stably share Earth's orbital neighborhood without colliding with it. It is one of a handful of known asteroids with an Earth-following orbit, a group that includes 3753 Cruithne, and the only known asteroid in an horseshoe orbit with Earth. It is, however, neither an Aten asteroid nor an Apollo asteroid because the semi-major axis of its orbit is neither less than nor greater than 1 AU, but oscillates between approximately 0.996 and 1.004 AU, with a period of about 350 years. In its ~350 yr horseshoe cycle, it never approaches Earth more closely than about 0.15 AU, alternately trailing and leading.


(419624) 2010 SO16, Description
According to various simulations 2010 SO16 will remain in this orbit for at least 120,000 years and possibly for more than a million years, which is unusually stable compared to other similar objects. One reason for this stability is its low orbital eccentricity, <0.084{\displaystyle <0.084}.


(419624) 2010 SO16, Description
A precovery of 2010 SO16 may have been located in a 2005 Spitzer Space Telescope image.


(42301) 2001 UR163
(42301) 2001 UR163, prov. designation: 2001 UR163, is a resonant trans-Neptunian object and possible dwarf planet located in the outermost region of the Solar System. The object measures approximately 352 kilometers (220 miles) in diameter with a high albedo and stays in an uncommon orbital resonance (4:9) with Neptune. It has the reddest color (RR-U) of any object in the Solar System. It was discovered on 21 October 2001 by astronomers of the Deep Ecliptic Survey program at Kitt Peak National Observatory near Tucson, Arizona, United States. As of 2021, it has not been named.


(42301) 2001 UR163, Classification and orbit
2001 UR163 has been characterized as a dwarf planet candidate. Based on assumptions and estimates, Michael Brown gives it a "likely"-status on his website, which is the third highest status after "near certainty" and "highly likely" (also see his classification table).


(42301) 2001 UR163, Classification and orbit
The object orbits the Sun at a distance of 37.0–66.6 AU once every 372 years and 12 months (136,232 days; semi-major axis of 51.82 AU). Its orbit has an eccentricity of 0.29 and an inclination of 1° with respect to the ecliptic. It came to perihelion on 8 October 1937, and has since been moving away from the Sun. In 2006, it moved beyond a distance of 50 AU and is at 53.7 AU as of 2021. The body's observation arc begins with a precovery, published by the Digitized Sky Survey and taken at the Siding Spring Observatory in July 1982.


(42301) 2001 UR163, Numbering and naming
2001 UR163 was numbered (42301) by the Minor Planet Center on 26 May 2002 (M.P.C. 45686). As of 2021, it has not been named. Acoording to the established naming conventions, it will receive a mythological or mythic name (not necessarily from Classical mythology), in particular one associated with creation.


(42301) 2001 UR163, Physical characteristics
Lightcurve analysis shows only small deviations, suggesting that 2001 UR163 is a spheroid with small albedo spots. Observations with Spitzer's Infrared Array Camera were used to study the body's surface composition. The analyzed data indicate the presence of 20% water ice, 60% amorphous silicates, and 20% organic compounds, including complex ones such as tholins.


(42301) 2001 UR163, Physical characteristics, Diameter and albedo
2001 UR163 measures approximately 352 kilometers (220 miles) in diameter with a high albedo of 0.209.


(42301) 2001 UR163, Physical characteristics, Diameter and albedo
Based on previous estimates published on the Lightcurve Data Base and on Michael Brown's website, 2001 UR163 measures between 531 km (330 mi) and 583 kilometers (360 miles), using an assumed intermediate surface albedo of 0.09 to 0.10 with an absolute magnitude of 4.49 and 4.4, respectively.


(432949) 2012 HH2
(432949) 2012 HH2 is a resonant trans-Neptunian object, approximately 255 kilometers (160 miles) in diameter, located in the outermost region of the Solar System. It was discovered by Slovak astronomer Tomáš Vorobjov from images taken on the night of 19 April 2012, at the Astronomical Research Institute (H21) in Illinois, United States.


(432949) 2012 HH2, Orbit and classification
2012 HH2 is a resonant trans-Neptunian object in an uncommon 4:5 resonance with Neptune (DES: 5:4E). It orbits the Sun at a distance of 29.2–40.4 AU once every 205 years and 4 months (75,008 days; semi-major axis of 34.81 AU). Its orbit has an eccentricity of 0.16 and an inclination of 29° with respect to the ecliptic. It is currently 29.8 AU from the Sun.


(432949) 2012 HH2, Numbering and naming
This minor planet was numbered (432949) by the Minor Planet Center on 4 April 2015 (M.P.C. 93615). As of 2021, it has not been named.


(432949) 2012 HH2, Physical characteristics, Rotation period
As of 2021, no rotational lightcurve of 2012 HH2 has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.


(432949) 2012 HH2, Physical characteristics, Diameter and albedo
Johnston's Archive estimates a mean-diameter of 255 kilometers (160 miles), using a standard magnitude-to-diameter conversion with an assumed albedo of 0.09. Astronomer Mike Brown gives a nearly identical estimates of 253 kilometers (160 miles) for the object's diameter with an albedo of 0.08 and an absolute magnitude of 6.3.


(433953) 1997 XR2
(433953) 1997 XR2 is a sub-kilometer sized asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 4 December 1997, by the Lincoln Near-Earth Asteroid Research (LINEAR) program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.


(433953) 1997 XR2, Orbit and classification
The asteroid orbits the Sun at a distance of 0.9–1.3 AU once every 13 months (408 days). Its orbit has an eccentricity of 0.20 and an inclination of 7° with respect to the ecliptic.


(433953) 1997 XR2, Orbit and classification
It has an Earth minimum orbital intersection distance of 0.000135 AU, which corresponds to 0.05 lunar distances. The body's observation arc begins with its official discovery observation, as no precoveries were taken, and no prior identifications were made.


(433953) 1997 XR2, Impact risk
Between 2002 and 2006, 1997 XR2 was considered to have about a 1 in 10,000 chance of colliding with Earth on 1 June 2101, based on a 27-day observation arc following its discovery.


(433953) 1997 XR2, Impact risk
With an estimated mass of 1.7×1010 kilograms, it was ranked at level 1 on the Torino scale (0–10) of impact risk, and was the only near-Earth object to be ranked higher than zero until it was joined by 2004 VD17 at level 1 in November 2004, and then when 99942 Apophis – then known only by its provisional designation 2004 MN4 – was temporarily assessed at level four in December 2004. Both 2004 VD17 and 99942 Apophis are now rated at level zero.


(433953) 1997 XR2, Impact risk, Recovery
On 24 February 2006, 1997 XR2 was observed by the Mount Lemmon Survey after being lost for more than 8 years. The refinement of its orbit eliminated the possibility of impact in 2101. It is now known that on 20 November 2101, the asteroid will be 0.0392 AU (5,860,000 km) from Earth.


(433953) 1997 XR2, Physical characteristics
According to a generic conversion of absolute magnitude to diameter, 1997 XR2 measures 200 to 230 meters.


(434326) 2004 JG6
(434326) 2004 JG6, provisional designation 2004 JG6 is an eccentric, sub-kilometer sized asteroid, classified as near-Earth object and potentially hazardous asteroid of the Atira group, which is also known as "Apohele" and "interior-Earth objects". It is one of the closest orbiting objects to the Sun.


(434326) 2004 JG6, Discovery
2004 JG6 was discovered on 11 May 2004, by leading astronomer Brian Skiff of the Lowell Observatory Near-Earth Object Search (LONEOS) at Anderson Mesa Station near Flagstaff, Arizona, United States.


(434326) 2004 JG6, Discovery
The body's observation arc begins with its official discovery observation at Anderson Mesa, as no precoveries were taken and no prior identifications were made.


(434326) 2004 JG6, Orbit and classification
It orbits the Sun at a distance of 0.3–1.0 AU once every 6 months (185 days). Its orbit has an eccentricity of 0.53 and an inclination of 19° with respect to the ecliptic.


(434326) 2004 JG6, Orbit and classification
2004 JG6 is the second known Atira asteroid –  the first being the group's namesake 163693 Atira –  which means its entire orbit lies within that of the Earth. Its orbital period is less than that of Venus, making it one of the closest known objects to the Sun, after Mercury. Due to its eccentric orbit, it crosses the orbits of both Mercury and Venus, which also makes it a Mercury- and Venus-crosser. It has an Earth minimum orbital intersection distance of 0.0381 AU (5,700,000 km) which translates into 14.8 lunar distances.


(434326) 2004 JG6, Physical characteristics
Based on a generic conversion from absolute magnitude, the asteroid measures between 0.6 and 1.4 kilometers in diameter.


(434620) 2005 VD
(434620) 2005 VD, provisional designation 2005 VD, is a centaur and damocloid on a retrograde orbit from the outer Solar System, known for having the second most highly inclined orbit of any small Solar System body, second to 2013 LA2. It was the most highly inclined known object between 2005 and 2013. The unusual object measures approximately 6 kilometers (3.7 miles) in diameter.


(434620) 2005 VD, Description
This minor planet was discovered on 1 November 2005, by astronomers of the Mount Lemmon Survey at Mount Lemmon Observatory near Tucson, Arizona. Precovery images have been found by the Sloan Digital Sky Survey (SDSS) from September 2005 and December 2001.


(434620) 2005 VD, Description, Classification
2005 VD has a semi-major axis greater than Jupiter and almost crosses the orbit of Jupiter when near perihelion. JPL lists it as a current centaur. Both the Deep Ecliptic Survey (DES), and the Minor Planet Center (MPC) have listed it as a centaur (qmin=~5AU) at different epochs. The DES and MPC will list as a centaur again in 2032.


(434620) 2005 VD, Description, Classification
Lowell Observatory also has it listed as a damocloid object.


(434620) 2005 VD, Description, Classification
2005 VD makes occasional close approaches to Jupiter, coming only 0.0817 AU from Jupiter in 1903, 0.0444 AU in 2057, and 0.077 AU in 2093. However the closest approach it will make in the next decade will only be 0.3089 AU on 17 December 2022.


(434620) 2005 VD, Description, Dynamics
Being a highly dynamic object, even among centaurs, 2005 VD's orbit has visibly changed even since its discovery. Between 1600 and 2400, its semimajor axis will slowly increase from 6.64 to 6.96 AU, its eccentricity slowly increasing from 0.27 to 0.34, and a decreasing inclination from 176.7° to 169.9°. As such, until about 1870, 2005 VD was the most highly inclined known asteroid in the Solar System.


(436724) 2011 UW158
(436724) 2011 UW158, provisionally known as 2011 UW158, is a stony, walnut-shaped asteroid and fast rotator, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters in diameter. It was discovered on 25 October 2011, by Pan-STARRS at Haleakala Observatory on the island of Maui, Hawaii, in the United States.


(436724) 2011 UW158, Orbital description
2011 UW158 orbits the Sun at a distance of 1.0–2.2 AU once every 2 years and 1 month (753 days). Its orbit has an eccentricity of 0.38 and an inclination of 5° with respect to the ecliptic. Its observation arc begins with its official discovery observation by Pan-STARRS, as no precoveries were taken, and no prior identifications were made.


(436724) 2011 UW158, Orbital description, Close approach
The asteroid has an Earth minimum orbit intersection distance of 0.0020 AU (300,000 km), which corresponds to 0.8 lunar distances (LD). On 19 July 2015, it passed about 2.5 million kilometers from Earth (6.5 LD), attracting the interest of astronomers. The asteroid was listed as level 1 in the Torino Scale on 4 November 2011, 9 days after its discovery, but was removed two weeks later.


(436724) 2011 UW158, Physical characteristics, Spectral type
2011 UW158 is an assumed stony S-type asteroid, the most common type among the populations of near-Earth and inner main-belt asteroids.


(436724) 2011 UW158, Physical characteristics, Diameter and albedo
Bruce Gary at Hereford Arizona Observatory (G95) estimated a mean-diameter of 220 meters with a high albedo of 0.39, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroid of 0.20 and calculates a mean-diameter of 311 meters based on an absolute magnitude of 19.9.


(436724) 2011 UW158, Physical characteristics, Fast rotator
In July and August 2015, rotational lightcurves of this asteroid were obtained from photometric observations by Bruce Gary at Hereford Arizona Observatory and by Brian Warner at the CS3–Palmer Divide Station in California (U82). Lightcurve analysis gave a rotation period of 0.6107 hours (36.6 minutes) with a brightness variation between 0.52 and 2.05 magnitude (U=3/3/3). This makes 2011 UW158 one of the Top 200 fast rotator, suggesting it is a large boulder rather than a rubble pile.


(436724) 2011 UW158, Physical characteristics, Shape
Radar observations by the Arecibo Observatory on 14 July 2015, revealed that the asteroid's shape looks like an unshelled walnut with a diameter of 300 by 600 metres. The radiometric observations also agreed with the previously obtained photometric ones and gave a period of 37 minutes.


(436724) 2011 UW158, Media attention
It also attracted the media and even firms such as Planetary Resources for its alleged content of platinum worth as high as 5 trillion U.S. dollars. Commenters at StackExchange have denied these estimations as being "orders of magnitude too high", and radar observations have shown that the object contains no more metal than an average rocky asteroid.


(444004) 2004 AS1
(444004) 2004 AS1, provisional designation 2004 AS1, and also known by the temporary name AL00667, is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the  Apollo group, approximately 300 meters in diameter.


(444004) 2004 AS1
It was discovered on 13 January 2004, by astronomers of the LINEAR program at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.


(444004) 2004 AS1, Description
Based on the asteroids brightness and assumed proximity to Earth, the asteroid was originally estimated to be only 30 meters in diameter.


(444004) 2004 AS1, Description, Orbit and classification
2004 AS1 orbits the Sun at a distance of 0.88–1.26 AU once every 13 months (405 days; semi-major axis of 1.07 AU). Its orbit has an eccentricity of 0.17 and an inclination of 17° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Socorro in January 2004.


(444004) 2004 AS1, Description, Close approaches
Although rather ordinary, it caused some controversy in astronomical circles due to initial projections posted on the web by the Minor Planet Center (MPC) suggesting an imminent collision with Earth on or about January 15 with a likelihood of 1:4. These projections came from very early observations, and turned out to be inaccurate (which is an ordinary occurrence in astronomy, as new observations refine the projected path of an object). In fact, the poster at the MPC had not realised that the data he had posted was essentially an impact prediction.


(444004) 2004 AS1, Description, Close approaches
The asteroid passed Earth on 16 February 2004 at a distance of 0.08539 AU (12,774,000 km; 7,937,000 mi)(or 33 times the distance from Earth to the Moon), posing no threat. It is an Apollo asteroid, with perihelion at 0.88 AU, a rather low eccentricity of 0.17, an inclination of 17° and an orbital period of 1.11 years.


(444004) 2004 AS1, Description, Diameter and albedo
Based on a generic magnitude-to-diameter conversion, 2004 AS1 measures between 240 and 480 meters in diameter, for a measured absolute magnitude of 20.5, and an assumed albedo of 0.20 and 0.05, which corresponds to a body with a stony and carbonaceous composition, respectively.


(444030) 2004 NT33
(444030) 2004 NT33 is a classical trans-Neptunian object and possible dwarf planet of the Kuiper belt in the outermost region of the Solar System, approximately 450 kilometers in diameter. It was discovered on 13 July 2004, by astronomers at Palomar Observatory, California, United States.


(444030) 2004 NT33, Orbit and classification
2004 NT33 is a "cubewano", a classical, low-eccentricity object in the Kuiper belt, that orbits the Sun at a distance of 36.8–50.0 AU once every 286 years and 2 months (104,527 days). Its orbit has an eccentricity of 0.15 and an inclination of 31° with respect to the ecliptic. It is currently 39 AU from the Sun.


(444030) 2004 NT33, Orbit and classification
A first precovery was taken at the Siding Spring Observatory in 1982, extending the body's observation arc by 22 years prior to its official discovery observation at Palomar.


(444030) 2004 NT33, Physical characteristics, Rotation period
In 2009, astronomers obtained a rotational lightcurve of 2004 NT33 from photometric observations, which were taken at the Galileo National Telescope (TNG) on the island of La Palma, and at the Sierra Nevada Observatory in Granada, both located in Spain. The ambiguous lightcurve gave a rotation period of 7.87 hours with a low brightness amplitude of 0.04 magnitude (U=1).


(444030) 2004 NT33, Physical characteristics, Diameter and albedo
According to the "TNOs are Cool" survey, using observations from the space-based Herschel and Spitzer telescopes, 2004 NT33 measures 423 kilometers in diameter and its surface has a visual geometric albedo of 0.125, while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and calculates a diameter of 482.53 kilometers with on an absolute magnitude of 4.7. Michael Brown estimates a larger diameter of 513 kilometers, based on a geometric albedo of 0.08 and an absolute magnitude of 4.9, which makes it a "highly likely dwarf planet" according to his assessment.


(445473) 2010 VZ98
(445473) 2010 VZ98, provisional designation 2010 VZ98,  is a trans-Neptunian object of the scattered disc, orbiting the Sun in the outermost region of the Solar System. With a diameter of approximately 450 kilometers, it is possibly a dwarf planet.


(445473) 2010 VZ98
It was discovered on 11 November 2010, by American astronomers David Rabinowitz, Megan Schwamb and Suzanne Tourtellotte at ESO's La Silla Observatory site in northern Chile, when it was 38 AU from the Sun.


(445473) 2010 VZ98, Orbit and classification
2010 VZ98 orbits the Sun at a distance of 34.3–266.6 AU once every 1846 years (674,262 days; semi-major axis of 150.5 AU). Its orbit has a high eccentricity of 0.77 and an inclination of 5° with respect to the ecliptic. Small number statistics suggest that this body may be trapped in a 3:2 orbital resonance with an unseen planet beyond Neptune with a semi-major axis of 195–215 AU. The first precovery was taken by the Sloan Digital Sky Survey at the Apache Point Observatory in 1998, extending the body's observation arc by 12 years prior to its discovery. The precoveries were found in May 2015 (MPS 604632).


(445473) 2010 VZ98, Physical characteristics
A rotational lightcurve of 2010 VZ98 was obtained from photometric observation by members of the Carnegie Institution for Science at Las Campanas Observatory, Chile. The light-curve gave a rotation period of 9.72±0.05 hours with a brightness variation of 0.18 magnitude (U=n.a. ).


(445473) 2010 VZ98, Physical characteristics, Diameter and albedo
While American astronomer Michael E. Brown assumes a diameter of 471 kilometers and an albedo of 0.07, the Johnston's Archive estimates a diameter of 443 kilometers with generic albedo of 0.09. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and calculates a diameter of 401 kilometers. These estimates are based on an absolute magnitude between 5.0 and 5.3.


(44594) 1999 OX3
(44594) 1999 OX3 is an eccentric trans-Neptunian object with a centaur-like orbit from the outer Solar System, approximately 150 kilometers in diameter. It was discovered on 21 July 1999, by astronomers John Kavelaars, Brett Gladman, Matthew Holman and Jean-Marc Petit at Mauna Kea Observatories, Hawaii, United States.


(44594) 1999 OX3, Orbit and classification
1999 OX3 orbits the Sun at a distance of 17.6–46.6 AU once every 181 years and 9 months (66,375 days). Its orbit has an eccentricity of 0.45 and an inclination of 3° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Mauna Kea in 1999.