Astronomers discover planet with scorching snow

Some real science from Penn State:

Astronomers discover sunscreen snow falling on hot exoplanet

Astronomers at Penn State have used the Hubble Space Telescope to find a blistering-hot giant planet outside our solar system where the atmosphere “snows” titanium dioxide — the active ingredient in sunscreen. These Hubble observations are the first detections of this “snow-out” process, called a “cold trap,” on an exoplanet. This discovery, and other observations made by the Penn State team, provide insight into the complexity of weather and atmospheric composition on exoplanets, and may someday be useful for gauging the habitability of Earth-size planets.

This illustration shows the seething hot planet Kepler-13Ab that circles very close to its host star, Kepler-13A. In the background is the star’s binary companion, Kepler-13B, and the third member of the multiple-star system is the orange dwarf star Kepler-13C. The alien world, called a ‘hot Jupiter,’ is actually six times more massive than Jupiter. Unlike chilly Jupiter, this exoplanet is one of the hottest known of the hot Jupiters, with a dayside temperature of nearly 5,000 degrees Fahrenheit. Another difference between Jupiter and Kepler-13Ab is that the exoplanet is so close to its star that it is tidally locked. One side keeps a permanent face to the star, and the other side is perpetually dark. On the nighttime side, the planet’s immense gravity pulls down titanium oxide condensates as snow. Hubble observations of the planet’s atmospheric temperature profile represent the first time astronomers have detected this precipitation process, called a “cold trap,” on an exoplanet. Without titanium oxide to absorb incoming starlight on the daytime side, the atmospheric temperature grows colder with increasing altitude. Normally, titanium oxide in the atmospheres of hot Jupiters absorbs light and reradiates it as heat, making the atmosphere grow warmer at higher altitudes. The Kepler-13 system is 1,730 light-years from Earth. CREDIT NASA, ESA, and G. Bacon (STScI)


“In many ways, the atmospheric studies we’re doing now on these gaseous ‘hot Jupiter’ kinds of planets are test beds for how we’re going to do atmospheric studies of terrestrial, Earth-like planets,” said Thomas Beatty, assistant research professor of astronomy at Penn State and the lead author of the study. “Understanding more about the atmospheres of these planets and how they work will help us when we study smaller planets that are harder to see and have more complicated features in their atmospheres.”

The team’s results are published in October 2017 issue of The Astronomical Journal.

Beatty’s team targeted planet Kepler-13Ab because it is one of the hottest of the known exoplanets. Its dayside temperature is nearly 5,000 degrees Fahrenheit. Kepler-13Ab is so close to its parent star that it is tidally locked, so one side always faces the star while the other side is in permanent darkness. The team discovered that the sunscreen snowfall happens only on the planet’s permanent nighttime side. Any visitors to this exoplanet would need to bottle up some of that sunscreen, because they won’t find it on the sizzling-hot daytime side.

The astronomers didn’t go looking for titanium oxide specifically. Instead, their studies revealed that this giant planet’s atmosphere is cooler at higher altitudes — which was surprising because it is the opposite of what happens on other hot Jupiters. Titanium oxide in the atmospheres of other hot Jupiters absorbs light and reradiates it as heat, making the atmosphere grow warmer at higher altitudes. Even at their much colder temperatures, most of our solar system’s gas giants also have warmer temperatures at higher altitudes.

Intrigued by this surprising discovery, researchers concluded that the light-absorbing gaseous form of titanium oxide has been removed from the dayside of planet Kepler-13Ab’s atmosphere. Without the titanium oxide gas to absorb incoming starlight on the daytime side, the atmospheric temperature there grows colder with increasing altitude.

The astronomers suggest that powerful winds on Kepler-13Ab carry the titanium oxide gas around, condensing it into crystalline flakes that form clouds. Kepler-13Ab’s strong surface gravity — six times greater than Jupiter’s — then pulls the titanium oxide snow out of the upper atmosphere and traps it in the lower atmosphere on the nighttime side of the planet.

This artist’s illustration shows the gas giant planet Kepler-13Ab as compared in size to several planets in our solar system. The behemoth exoplanet is six times more massive than Jupiter. Kepler-13Ab is also one of the hottest known planets, with a dayside temperature of nearly 5,000 degrees Fahrenheit. It orbits very close to the star Kepler-13A, which is 1,730 light-years from Earth. Credit: NASA, ESA, and A. Feild (STScI)

“Understanding what sets the climates of other worlds has been one of the big puzzles of the last decade,” said Jason Wright, associate professor of astronomy at Penn State, and one of the study’s co-authors. “Seeing this cold-trap process in action provides us with a long sought and important piece of that puzzle.”

The team’s observations confirm a theory from several years ago that this kind of precipitation could occur on massive, hot planets with powerful gravity. “Presumably, this precipitation process is happening on most of the observed hot Jupiters, but those gas giants all have lower surface gravities than Kepler-13Ab,” Beatty explained. “The titanium oxide snow doesn’t fall far enough in those atmospheres, and then it gets swept back to the hotter dayside, revaporizes, and returns to a gaseous state.”

The researchers used Hubble’s Wide Field Camera 3 to conduct spectroscopic observations of the exoplanet’s atmosphere in near-infrared light. Hubble made the observations as the distant world traveled behind its star, a transit event called a secondary eclipse. This type of transit yields information on the temperature of the components of the atmosphere on the exoplanet’s dayside.

“These observations of Kepler-13Ab are telling us how condensates and clouds form in the atmospheres of very hot Jupiters, and how gravity will affect the composition of an atmosphere,” Beatty explained. “When looking at these planets, you need to know not only how hot they are, but also what their gravity is like.”


The research team led by Thomas Beatty includes Ming Zhao, Jason Wright, and Ronald Gilliland (Penn State University, University Park), Nikku Madhusudhan (University of Cambridge, U.K.), Angelos Tsiaras (University College London, U.K.), and Avi Shporer and Heather Knutson (California Institute of Technology, Pasadena, California).


This research was funded by NASA and the Penn State Center for Exoplanets and Habitable Worlds.

The paper:;



We observed two eclipses of the Kepler-13A planetary system, on UT 2014 April 28 and UT 2014 October 13, in the near-infrared using Wide Field Camera 3 on the Hubble Space Telescope. By using the nearby binary stars Kepler-13BC as a reference, we were able to create a differential light curve for Kepler-13A that had little of the systematics typically present in HST/WFC3 spectrophotometry. We measure a broadband (1.1–1.65 μm) eclipse depth of 734 ± 28 ppm and are able to measure the emission spectrum of the planet at R ≈ 50 with an average precision of 70 ppm. We find that Kepler-13Ab possesses a noninverted, monotonically decreasing vertical temperature profile. We exclude an isothermal profile and an inverted profile at more than 3σ. We also find that the dayside emission of Kepler-13Ab appears generally similar to an isolated M7 brown dwarf at a similar effective temperature. Due to the relatively high mass and surface gravity of Kepler-13Ab, we suggest that the apparent lack of an inversion is due to cold-trap processes in the planet’s atmosphere. Using a toy model for where cold traps should inhibit inversions, as well as observations of other planets in this temperature range with measured emission spectra, we argue that with more detailed modeling and more observations we may be able to place useful constraints on the size of condensates on the daysides of hot Jupiters.


66 thoughts on “Astronomers discover planet with scorching snow

  1. WOW ! 5,000 degrees. Do you think we can fit this one on Nikolov & Zeller’s pressure/density graph?


    Yes, Such pressing scientific questions that need to be addressed to society … when you’re carrying $20 Trillion in debt.

    • So instead of spending money on hard science we should spend it on CAGW “research”?

      We can spend OUR money on whatever the hell we want to. And the whole world benefits from our largess.

      • If anything, their focus on particulate size to me is the problem. It forms an end-goal with no practical value. The goal should be refinement of modeling the measured light curves with the hope that someday, light curves from exo-Earth-sized cool planets (300K) can be analyzed (as telescopes get better, Webb for ex.).

        The goal should be to definitively detect molecular oxygen (O2 and O3) in an exo-atmosphere. Free molecular oxygen (21% in Earth’s case) is the unmistakable sign of biological activity. It could also be chlorophyll if the parent star has an approx 5800K surface like our sun. But an exo-chlorophyll-like signature will depend on the accompanying star’s “visible” emission spectra and that is of course dependent on the star’s surface temp. Earth’s chlorophyll signature evolved to optimize harvest the blue-green frequency photons from our sun.

        Of course in this study presented here, they used the accompanying binary pair (binary stars Kepler-13BC as a reference) to eliminate “systematics.” An Earth-like planet with multi-billion year evolved life and an extensively remodeled geo-biosphere probably needs the orbital stability of a unitary star system.

      • Joel

        that is an explanation of a subject I know nothing about, well illustrated.

        Personally, however, I think the Western world is now obsessed with science and it risks turning into the phenomenon it rescued us from, religion. Indeed, climate change is doing just that.

        We have far more important things to focus our efforts on than staring at the stars e.g. understanding how the oceans of the earth can be used as a sustainable farm to feed a growing population; how can we lift the developing world from poverty and stabilise population growth; how can we harmonise extreme political and religious beliefs; how can we turn the tide of politicisation of everything, with it’s inherent, rampant corruption, and expansion into small organisations focussed on local issues, rather than international behemoths focussed on global management.

        We may imagine the UN and the World Bank are forces for good, and they originally were, but they are now being used by every political organisation in the world to manipulate circumstances to their advantage, whatever that may be.

        Humanity is a tribal community. Global harmonisation is a pipe dream until everyone has the opportunity to compete on a level playing field for their right to personal achievement. That, in my opinion, can only be realised through trade, the defining quality of mankind over every other organism on the planet.

        We have millions of years before the earth is consumed by the sun, why are we wasting our efforts on space exploration when there is so much that is unknown about our own home.

      • Sorry, my first statement read as though the science of climate change is rescuing us from scientific religion. That’s not what I meant. It is of course immersing the Western world in scientific religion.

      • Why should anyone suppose that the particular molecule used by plants on Earth is the only possible one that can perform this function?
        It would be more logical to assume there are large, and possibly an infinitely large, number of chemical combinations that could perform the function of chlorophyll, and chlorophyll was a random happenstance.

      • Since the spectra of other stars are likely to differ from the Sun’s, pigments besides chlorophyll are liable to evolve on other worlds supporting life.

        Even on Earth, plants use other pigments besides chlorophyll to absorb light. They also employ pigments such as carotenes and xanthophylls. In addition to chlorophyll, green algae use phycocyanin, carotenes and xanthophylls. Red algae use phycoerythrin, and brown algae and diatoms fucoxanthin, resulting a variety of colors.

        Before chlorophyll evolved, the first photosynthetic organisms probably used reducing agents such as hydrogen or hydrogen sulfide, rather than water, as electron sources.

      • joelobryan October 29, 2017 at 12:11 pm


        It is not. It can be the sign of Hydrogen escaping to space from an Earth sized planet as well. Which would happen here, if there were no cold trap at the top of tropsphere freezing all water out before it could meet hard UV radiation.

  3. Is it titanium dioxide or titanium oxide? Some of the non chemists may think they are different things. Titanium dioxide (TiO2) is referred to in the first sentence, but titanium oxide is used throughout the rest of the body of the article.

  4. I’m missing something here. If TiO2 condenses out of the nighttime atmosphere and falls as “snow” wouldn’t this eventually deplete the atmosphere of TiO2?

    • And how deep is it after all this time?
      And if there is enough to precipitate out on the night side, how is it they are saying there is none on the day side. where it must obviously be being vaporized from the surface by the intense heat and/or sunlight?
      I am thinking these “observations” are one part measurements of wavelengths, and about a hundred parts inference or modelled results.
      Language like “The team’s observations confirm a theory from several years ago…” make it sound like they got this all sewn up and the stated information is factual, rather than someone’s idea of what might be occurring.
      Considering how many surprises we find in our own solar system every time we even look at a new moon, asteroid, or comet, I really doubt never wrong genii at NASA have really “confirmed” anything, at least not in the sense of the word that most people would accept as actual confirmation…i.e., beyond all doubt.
      But we already have a very good how these sciencey folks at NASA have twisted up the scientific process, and of their descriptions of what they do, and of what they “know”. They regard their ideas as virtually factual using the criteria of “We can’t think of any other way to explain what we think we are seeing, therefore we must be correct”.
      Take anything you are hearing for the first time with a giant grain of salt.
      They speak like they are unaware how often they have to retract, revise, rewrite, or just plain toss out and start over on.
      The worst part is, they have made such a mess of their own credibility, it is impossible to gage how much credibility to give anything they say.
      Not to mention difficult to know whether the press release matches what the researchers have reported.

    • There likely isn’t a solid surface on which it falls/settles. Rather it reaches another denser fluid layer that transports it back to hot side for reheating and recycling. Think fluids in motion, density gradients, and discontinuities between thermal layers with no solid surfaces.

      • At those temperatures (of the sunlit side) there are no condensates (which they detect the spectral signature of the TiO condensate), only hot metal vapor.

      • From the article:


        No TiO2 gas, that was the point of the article.

      • Current proto-disc evolutionary models have the gas giants forming just beyond the freeze line, a freeze line dictated by the parent star’s irradiance. The rocky inner planets form (gravitationally coalesce) from heavier elements in the protodisc material that aren’t immediately swept away by the early stellar winds. The hot Jupiter scenario requires the gas-giant to migrate inward after formation. As it approaches the inner planets, gravitational choos ensues. It smashes, absorbs, and kicks out into cold interstellar space the smaller rocky planets, like a Bull charging through a China shop. It can acquire metals in its super-heated atmosphere in the process of tidally and absorbing some of the inner rocky planet materials.

    • The currently accepted explanation of how planets form, and the separation with distance of rocky vs gaseous planets due to the “frost line”, makes one wonder how a Jupiter-like planet could exist in such close proximity to the parent star.
      It could not have formed there…it must be there temporarily at best.
      A little bit of checking did not turn up the steller classification of the parent star, but as drawn, it would appear to be a hot massive star, which would imply a fierce steller wind, which would be ablating such a planet very rapidly.

      • Hot Jupiters are common. Since they’re big, it’s easier to find them. But, still, it’s surprising how many big planets there are orbiting close to their stars.

  5. 5000 degrees is blistering hot?
    No, 200 degrees will give you blisters.
    5000 degrees will instantly vaporize you into incandescent plasma, faster than you can say “At least it is a dry heat”.
    Just sayin’.

    • Yup.
      That is about all that modern cosmologists and theoretical physicists do.
      Imagine, and report what they imagine as if they have discovered something.

  6. “Science” by press release, written by a journalism major.
    There might be some interesting science in there somewhere, but with this kind of reporting, we will never know.

    Garbage. Pure junk.

    • The science paper is an advertisement for the science
      The news article is an avertisement for the science paper.

      if we only read the news, yes, then “we will never know”

      That’s why you dont get your science from the news, either new news
      or old press clippings ala heller.

      • Tony typically highlights the exact quotes from that era’s “experts.” in those news clippings

        Unlike today’s Borenstein’s, Romm’s, and Fake Science Guys, those journalists of a bygone era didn’t presume to be experts in the subjects on which they reported.

        For his efforts, Tony undoubtedly has put himself on the list of some very powerful, evil people who have vested financial interests in the hustle with his steady take-down of the temperature record manipulators.

      • Careful Steve we could put Best and most of climate science in the News category.,is your field results 5 sigma. Remember anything less is just a statistical bump 🙂

      • That’s very true Steven, tho, if you try to understand Heller’s perspective, when he produces a historical news clipping it is usually always in the context of a factual event, for example, it was claimed that there was no “global cooling” scare in the 1970’s, Heller used Media clippings from that time to show that there was a global cooling scare. It’s obvious that there was news of global cooling, if that isn’t enough, look at the names in the article clippings for yourself, it was their opinion being expressed at the time in an authoritative manor.

  7. Kepler 13A, B, C is a triple star system. It’s distance from Earth is somewhere between 1726 and 2075 light years from Earth.

    That info is provided just in case anyone wants to book a Space X flight to that system.

    There’s a lot of uncertainty in that report. It comes off as being rather tentative, partly having to do with finding things that were not expected and then trying to explain them.

    Thanks for the heads up, Anthonry.

    • But that is not how it reads to me…in fact it is stated that such study will inform how they determine the climate and atmospheres of smaller terrestrial planets.
      They speak of conclusions and confirmation as if they have anything nailed down…I do not see much in the way of discussion of uncertainly, or of the highly speculative nature of such observations on tiny amounts of data.

      • The process, the methodology, and their steady refinements in the mathematical techniques of observations iare the value-added. Knowing the condensate particle size of TiO on a hot Jupiter 2000 ly distant is rather useless info IMO.

        It’s the T-shirt saying: Happiness is the journey, not the destination.

  8. Kepler-13Ab is a big hot Jupiter. Its mass is estimated at about 5 to 8 Jupiters. The lower limit for brown dwarfs, substellar objects more massive than planets but less so than stars, is around 13 MJ.

    Also Kepler-13A is a hot star, as can be seen. Tidal locking is more commonly associated with smaller, cooler stars, at least in popular imagination if not in the universe. Mercury isn’t tidally locked to the sun. It rotates exactly three times for every two times it revolves around the Sun.

      • As I noted. Tidally locked means 1:1. ie the locked body always presents the same face to the object it orbits.

        The Mercury and the sun and the moons of Jupiter are in “spin-orbit resonance”, not fully tidally locked.

      • >>
        . . . the moons of Jupiter are in “spin-orbit resonance”, not fully tidally locked.

        I don’t know what you’re talking about. You can be tidally locked and not in a ratio of 1:1. However, I believe all the moons of Jupiter are tidally locked in a 1:1 ratio with their primary. In addition, the three inner Galilean moons (Io, Europa, and Ganymede) are in an orbital resonance of 4:2:1. Callisto is almost in a resonance of 8:4:2:1, but not quite.


      • It’s simple.

        Mercury is not tidally locked, but in 2:3 spin-orbit resonance. It doesn’t always present the same face toward the Sun.

        Yes, Ganymede is tidally locked, with one side always facing toward Jupiter. The two inner Galilean moons Eo and Europa are in 1:2:4 orbital resonance.

        The point is that there is a distinction between being “tidally locked” and in a “spin-orbit resonance”, ie not such as to keep one face always toward the central body.

      • I went to Wikipedia, which doesn’t cite a source, but says it considers synchronous rotation a special case of tidal locking, in which case you’re right. It requires practically no eccentricity.

        “In the special case where the orbital eccentricity is nearly zero, tidal locking results in one hemisphere of the revolving object constantly facing its partner, an effect known as synchronous rotations.”

      • It depends on what your definition of tidal locking is. If it’s 1:1, then Mercury isn’t tidally locked. I’ve read for many years that Mercury is the only tidally locked object in the Solar System that’s isn’t in a ratio of 1:1. So I appreciate your investigation. Before your last comment, I was simply going to agree to disagree with you (and not comment further). I do agree that Mercury is a special case.


  9. Titanium is terravalent like carbon.
    One wonders if at a suitable temperature and pressure it would polymerise and form the basis of complex molecules?

    • Are you suggesting their could be life in the Universe based on chemistry completely different that what is found on Earth?
      That sounds like something someone with an open mind would say.

      • Titanium Carbide [TiC] has a cubic crystal structure and a boiling point of 5720 degrees F.
        You might get it in the “snow” around on the dark side as well as TiO2 but it’s hard to see it forming complex molecules which might lead to “life”.
        The same for Titanium Nitride [TiN] and Titanium Phosphide [TiP].
        Titanium Sulphide [TiS2] might form more complex structures a bit like carbon. It has a melting point of 1780 degrees C so might be present on the “cool ” side

  10. I wonder what percentage of solar system debris is thrown out into the greater universe when these hot Jupiters migrate into the inner solar system.

    What percentage is ejected during the formation of a solar system like ours, which has no hot Jupiter?

    • Closest I can come to an answer to that, is this article:

      They believe that Jupiter moved only a little, and that thinned the asteroid belt.

  11. This has to be said, until we actually go and visit one of these planetary systems and confirm even one of the most conservative results,(hard proof much?) we are stuck with the fact, all this research into exo-planetary systems should be grounded in reality, lest we end up with a Galaxy full of fantasy worlds and an augmented reality of the universe… It should also be pointed out that futurists such as Michio kaku and Neil deGrasse Tyson and others are leading the way to build a fantasy wonderland and destroying our understanding of the universe.

  12. Has anyone noticed that NASA seldom shows actual photos? Here is a story hyped with artist’s illustrations but no Hubble photos, probably because they are too boring and because they would call into question the speculations about the planet. Just more sci-fi from NASA.

    This was most evident during the Juno probe approach to Jupiter. Rather than show the historic photos, they showed computer animations of the probe approaching and orbiting the planet, as if the probe were taking selfies. Apparently, reality doesn’t serve up enough excitement.

    • Yeah, the NASA Climate Change Charlatans have sullied the reputation of the entire NASA organization.

      It’s too bad because NASA does some very good things, and has some very good people working there.

  13. Someone needs to start making appointments with these retarded “reporters” to shoot them in the genitals with 10g rocksalt rounds. Its gotten so anything can be posted on the internet and believed.

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