Researchers use Hubble Telescope to reveal cloudy weather on alien world

Dec 31, 2013
This image shows an artist's view of exoplanet GJ 1214b. Credit: NASA, ESA, & G. Bacon/STScI, STScI-PRC14-06

Weather forecasters on exoplanet GJ 1214b would have an easy job. Today's forecast: cloudy. Tomorrow: overcast. Extended outlook: more clouds.

A team of scientists led by researchers in the Department of Astronomy and Astrophysics at the University of Chicago report they have definitively characterized the of a super-Earth class planet orbiting another star for the first time.

The scrutinized planet, which is known as GJ1214b, is classified as a super-Earth type planet because its mass is intermediate between those of Earth and Neptune. Recent searches for planets around other stars ("exoplanets") have shown that super-Earths like GJ 1214b are among the most common type of planets in the Milky Way galaxy. Because no such planets exist in our Solar System, the physical nature of super-Earths is largely unknown.

Previous studies of GJ 1214b yielded two possible interpretations of the planet's atmosphere. Its atmosphere could consist entirely of or some other type of heavy molecule, or it could contain high-altitude clouds that prevent the observation of what lies underneath.

But now a team of astronomers led by UChicago's Laura Kreidberg and Jacob Bean have detected clear evidence of clouds in the atmosphere of GJ 1214b from data collected with the Hubble Space Telescope. The Hubble observations used 96 hours of telescope time spread over 11 months. This was the largest Hubble program ever devoted to studying a single exoplanet.

The researchers describe their work as an important milestone on the road to identifying potentially habitable, Earth-like planets beyond our Solar System. The results appear in the Jan. 2 issue of the journal Nature.

This rendering shows the size of GJ 1214b and another, larger exoplanet compared to Earth and Neptune. Credit: NASA & ESA, STScI-PRC14-06b

"We really pushed the limits of what is possible with Hubble to make this measurement," said Kreidberg, a third-year graduate student and first author of the new paper. "This advance lays the foundation for characterizing other Earths with similar techniques."

"I think it's very exciting that we can use a telescope like Hubble that was never designed with this in mind, do these kinds of observations with such exquisite precision, and really nail down some property of a small planet orbiting a distant star," explained Bean, an assistant professor and the project's principal investigator.

GJ 1214b is located just 40 light-years from Earth, in the direction of the constellation Ophiuchus. Because of its proximity to our and the small size of its host star, GJ 1214b is the most easily observed super-Earth. It transits, or passes in front of its parent star, every 38 hours, giving scientists an opportunity to study its atmosphere as starlight filters through it.

Kreidberg, Bean and their colleagues used Hubble to precisely measure the spectrum of GJ 1214b in near-infrared light, finding what they consider definitive evidence of high clouds blanketing the planet. These clouds hide any information about the composition and behavior of the lower atmosphere and surface.

The planet was discovered in 2009 by the MEarth Project, which monitors two thousand red dwarf stars for transiting planets. The planet was next targeted for follow-up observations to characterize its atmosphere. The first spectra, which were obtained by Bean in 2010 using a ground-based telescope, suggested that the planet's atmosphere either was predominantly water vapor or hydrogen-dominated with high-altitude clouds.

More precise Hubble observations made in 2012 and 2013 allowed the team to distinguish between these two scenarios. The news is about what they didn't find. The Hubble spectra revealed no chemical fingerprints whatsoever in the planet's atmosphere. This allowed the astronomers to rule out cloud-free atmospheres made of water vapor, methane, nitrogen, carbon monoxide, or carbon dioxide.

The best explanation for the new data is that there are high-altitude clouds in the atmosphere of the planet, though their composition is unknown. Models of super-Earth atmospheres predict clouds could be made out of potassium chloride or zinc sulfide at the scorching temperatures of 450 degrees Fahrenheit found on GJ 1214b. "You would expect very different kinds of clouds to form than you would expect, say, on Earth," Kreidberg said.

The launch of NASA's next major space telescope, the 6.5m James Webb Space Telescope (JWST), later this decade should reveal more about such worlds, Kreidberg said. "Looking forward, JWST will be transformative," she said. "The new capabilities of this telescope will allow us to peer through the on planets like GJ 1214b. But more than that, it may open the door to studies of Earth-like planets around nearby stars."

Explore further: 'Blockbuster' science images

More information: "Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b," by Laura Kreidberg, Jacob L. Bean, Jean-Michel Désert, Björn Benneke, Drake Deming, Kevin B. Stevenson, Sara Seager, Zachory Berta-Thompson, Andreas Seifahrt, & Derek Homeier. dx.doi.org/10.1038/nature12888

Related paper: dx.doi.org/10.1038/nature12887

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Sinister1812
5 / 5 (1) Dec 31, 2013
So this planet here... Are we talking super-Venus?
GSwift7
5 / 5 (6) Dec 31, 2013
wow, that's really cool. Not only did they make a significant finding, they are also working out analytical methods which increase the power of other existing and future telescopes; it's a force multiplier, in other words.

This is also interesting because they were able to make an entirely new type of observation on the aging Hubble telescope. Damn, we've sure gotten our money's worth out of that machine. Hubble wrote so many new pages in the books that it's hard to know where to begin.

The result of high clouds isn't surprising really, but our ability to 'observe' them is. I think we will see a lot of planets that resemble Venus more than Earth (like this one), but I also suspect that Earth-like planets aren't rare either. Once we get observations good enough to spot the smaller planets, I think we will find an abundance of them. And I suspect that Earth-sized planets in the right orbit will tend to be Earth-like in general (though age is a factor).
GSwift7
5 / 5 (4) Dec 31, 2013
So this planet here... Are we talking super-Venus?


We don't have direct evidence yet, but that's what it looks like. By eliminating the possibility that it has a water-rich clear atmosphere, it basically leaves no other known option but a super-Venus. That shouldn't be surprising really. Anything this close to its star seems like it should either be a super-Venus or stripped bare like Mercury, which I believe just depends on it's size/gravity.

It won't be too long before we start to get enough observations of this type to allow us to formulate some 'rules of thumb' about the factors that dictate general properties.
Modernmystic
2.6 / 5 (5) Dec 31, 2013
One of the interesting things that strikes me about this article isn't the cloud composition, but rather that clouds qua clouds seem to be quite common if not the general rule of atmospheres. I haven't thought about that enough to come to any epiphanies about what that means for "exo-climate" modeling or the nature of various atmospheres, but I suspect that before long we'll come to some relatively hard and fast "rules" or "laws" that govern ALL atmospheres, and hence learn something we didn't know about our own planet.
GSwift7
5 / 5 (6) Dec 31, 2013
One of the interesting things that strikes me about this article isn't the cloud composition, but rather that clouds qua clouds seem to be quite common if not the general rule of atmospheres. I haven't thought about that enough to come to any epiphanies about what that means for "exo-climate"


The chemical composition of Earth's atmosphere has been quite different over geological time scales. I wonder if we could look back at proto-Earth, would we see a cloud-covered planet?
Modernmystic
3.7 / 5 (6) Dec 31, 2013
One of the interesting things that strikes me about this article isn't the cloud composition, but rather that clouds qua clouds seem to be quite common if not the general rule of atmospheres. I haven't thought about that enough to come to any epiphanies about what that means for "exo-climate"


The chemical composition of Earth's atmosphere has been quite different over geological time scales. I wonder if we could look back at proto-Earth, would we see a cloud-covered planet?


Indeed! Something else I hadn't considered. One thing we should keep in mind when looking for Earth like planets in younger systems (say 1-2 billion years old) that we should be looking for a methane atmosphere, certainly no oxygen. if we don't consider this we could be skewing estimates of "truly" Earth like planets in the galaxy.
Q-Star
4.3 / 5 (8) Dec 31, 2013
Recent searches for planets around other stars ("exoplanets") have shown that super-Earths like GJ 1214b are among the most common type of planets in the Milky Way galaxy.


I know, I'm picking at nits, but I really wish this had been written: ,,,,"exoplanets (planets around other stars) have shown",,,,,, "Exoplanets" is the preferred and correct term, "planets around other stars" is the analogy or explaining term.

I'll take my drubbing for being so pedantic. Ya can have at me now.
Sinister1812
5 / 5 (2) Dec 31, 2013
We don't have direct evidence yet, but that's what it looks like. By eliminating the possibility that it has a water-rich clear atmosphere, it basically leaves no other known option but a super-Venus. That shouldn't be surprising really.


You're right, GSwift. Thanks for answering my question. And I couldn't agree more, there's probably even higher chance of finding Venus-like worlds.
cantdrive85
1 / 5 (8) Dec 31, 2013
Recent searches for planets around other stars ("exoplanets") have shown that super-Earths like GJ 1214b are among the most common type of planets in the Milky Way galaxy.


I know, I'm picking at nits, but I really wish this had been written: ,,,,"exoplanets (planets around other stars) have shown",,,,,, "Exoplanets" is the preferred and correct term, "planets around other stars" is the analogy or explaining term.

I'll take my drubbing for being so pedantic. Ya can have at me now.

Not so fastidious about "hot gas" are we...
cantdrive85
1 / 5 (7) Dec 31, 2013
It won't be too long before we start to get enough observations of this type to allow us to formulate some 'rules of thumb' about the factors that dictate general properties.

So much for the predictive abilities of your "theory".
Returners
1.3 / 5 (6) Dec 31, 2013
So this planet here... Are we talking super-Venus?


I think that would be true only in the sense of the extreme temperatures, but this planet is actually 400f cooler than Venus.

The scientists are making a best educated guess about the composition, since they can't detect the exact molecules. Potassium Chloride and/or Zinc are very heavy, very dense compared to the primary components of our own atmosphere.

I don't think it would be fair to expect to understand all planets of a given size according to the same chemical concepts, because their composition, not just the size and temperature, determines the possible core/crust/ocean/atmosphere scenarios.

There are any number of exotic, however unlikely, scenarios of conceivable planets which we don't normally think about.

i.e.
Metal core, no mantle or crust, covered in ocean or atmosphere.

All liquid and exotic ice core (unlikely).

hybrid terrestrial-gas giant

All could exist, with unique ranges of compositions.
Returners
1.2 / 5 (6) Dec 31, 2013
One thing that interests me is where the dividing line will be drawn between Super-Earth and the Hybrid Gas Giant concept.

Venus has about 100 atmospheres, but we still consider it a terrestrial planet. Will something be considered a "Hybrid" if it has a certain atmospheric pressure? Or will the determining point be what percentage of it's mass appears as a gas?

Perhaps if 50% of the planet's total mass is in gas phase, and it is at least 4 times the mass of Earth, but less than Neptune, then we would consider it a hybrid?

As far as I know, I am the only person who has mentioned the notion of making concrete distinctions between something that has the mass of a Super-Earth, but has Gas Giant properties, therefore why I used the term "Hybrid". I've never seen a astrophysicist use that term, nor the concept.

You can rule out the "hybrid" concept if you can prove the atmosphere is relatively thin, but with a thick atmosphere, it would be hard to tell the difference from afar.
Returners
1.3 / 5 (6) Dec 31, 2013
Indeed! Something else I hadn't considered. One thing we should keep in mind when looking for Earth like planets in younger systems (say 1-2 billion years old) that we should be looking for a methane atmosphere, certainly no oxygen. if we don't consider this we could be skewing estimates of "truly" Earth like planets in the galaxy.


You're making a mistake when assuming every object must follow an identical path to arrive at a similar destination.

It is conceivable that objects could start with different compositions, though certainly many ingredients overlapping, but perhaps different temperatures also, and in such a way allow for "skipping" steps in development that the other planet may have taken, but nonetheless ending much the same.

Simply put, chemicals which are stable at high temperature not the same as those at cold temperatures. If a planet forms cooler it can conceivably "skip" some of the stuff at the highest temperatures, but end up similar.
Torbjorn_Larsson_OM
4.3 / 5 (4) Dec 31, 2013
At 2.7 Earth radii [ ER; http://en.wikiped...J_1214_b ] it is too large to be a superEarth in newer planetary models, above ~ 2 ER it is likely a miniNeptune. Hence likely clouds. [I would give refs, but I doubt I have bookmarked this especially, it has been a consistent outcome of 2013 from early conferences on.]

Oh, and a creationist trolling. What a way to start the new year: same as the last 2000 years of total mistake on how nature works - and we have known that for 400 years now. (O.o)
Torbjorn_Larsson_OM
3 / 5 (2) Dec 31, 2013
@MM, G7: "I haven't thought about that enough to come to any epiphanies about what that means for "exo-climate" modeling or the nature of various atmospheres"; "I wonder if we could look back at proto-Earth, would we see a cloud-covered planet?"

Actually clouds seem vital for early Earth, when they started with the atmospheric global circulation models (GCMs) they solved how the constraints of low irradiance (from a young Sun @ ~ 75 % of today's) and early atmosphere (from the geological record) could be met without 100 % ice cover ("Snowball Earth"). It was a cloud albedo feedback above cold water, especially near the freezing line; when the clouds thins out, the albedo increases. [Cf "Exploring the faint young Sun problem and the possible climates of the Archean Earth with a 3-D GCM", Charnay et al, Journ. of Geophys. Res. 2013]

Another persistent feature then is polar caps, the periods when they haven't existed are shorter than the ones we have been without.
Torbjorn_Larsson_OM
4 / 5 (2) Dec 31, 2013
@MM: "One thing we should keep in mind when looking for Earth like planets in younger systems (say 1-2 billion years old) that we should be looking for a methane atmosphere, certainly no oxygen."

Traces of methane in some cases, because we didn't have much. Too much and haze formation would have meant a deep-frozen Earth, something not seen. (See the ref.)

Similarly in our case: the jury is still out on the exact history of free oxygen since the constraints are still arguable. But certainly the consensus is little to none in our case.

Methane is especially intriguing because aside from volcanism it appears out of serpentinization in a subducting crust. And that is precisely what, together with CO2 for half of the carbon, that went into the primordial metabolism of our most distant cousins the alkaline hydrothermal vents, according to Russel et al deep phylogeny. 2013 was the year when we answered the age old question "where did we come from".

Methane is an important bioconstraint.
Returners
1.5 / 5 (6) Dec 31, 2013
One possible solution to the "Faint young sun" paradox might be that either the the theoretical present age or the theoretical past luminosity of the Sun are incorrect.

What is the saying? The simplest explanation that works is probably the best.

You have to invent a lot of processes and leaps of the imagination to explain how the Earth could be relatively warm during a time period where the alleged amount of sunlight should have produced an Earth about 53C colder than present averages.

There are other explanations for anomalous temperature changes besides changes in atmospheric chemistry or the luminosity of the Sun. Planetary orbits could change, for example. Perhaps Jupiter somehow perturbed the orbits of Earth, Mars, and Venus, and swapped them up at one or more times in the past? Not so far-fetched as you might think, since mainstream theory already claims that Neptune and Uranus have swapped places at least once in the past.
Returners
1 / 5 (5) Dec 31, 2013
Ah, I see, the planet is definitely too "light" to be anything we would call a Terrestrial planet.

It's average density is only a third that of Earth, and it's "Surface" gravity (this would be the top of the atmosphere,) is actually less than Earth, because the density is so low.

I suppose you could calculate a "best case" for having terrestrial characteristics, i.e. the least dense Earth-like rocks and minerals of which the object could be made, but it's a bit of a stretch, seeing as how that average density is only slightly more than "Dry Ice".

Regardless, the implication is that if the planet is made of typical materials, then the majority of it's radius MOST likely is either liquid or gaseous, not solid.

I suppose there is an off chance it could be solid, and just made of something a lot less dense than the Earth, or a rock covered in thousands of miles thick of water (as mentioned in wiki,) or a hydrocarbon, but the latter seems unlikely.
Returners
1 / 5 (6) Dec 31, 2013
Anyway, the summary of both the Article and the discussion is as follows:

We've already found exo-planets which are a lot more Earth-like, within known science, than this particular ball of hell.
typicalguy
5 / 5 (2) Dec 31, 2013
They've really got to get away from calling these planets "super earth's". The general public is going to think it's a huge Earth but it's not. If the planet's gravity would crush a human like an aluminum can or the planet is so close to it's host star that it's temp is well above the boiling point of water then it's not a "super earth".
Captain Stumpy
5 / 5 (2) Jan 01, 2014
wow, that's really cool. Not only did they make a significant finding, they are also working out analytical methods which increase the power of other existing and future telescopes; it's a force multiplier, in other words.

This is also interesting because they were able to make an entirely new type of observation on the aging Hubble telescope. Damn, we've sure gotten our money's worth out of that machine.


and at 40 light years....

GSwift or Q-Star (or anyone that can answer):

they say that "according to models" in the article,
potassium chloride or zinc sulfide at the scorching temperatures of 450 degrees Fahrenheit

well, wouldn't the reflected light from the star at least provide spectra that they could analyse, given that they already have spectra data from the star?
or rather, wouldn't the reflected spectra from the clouds give them an idea of the composition of the clouds?
or is it too far away?
am i not understanding it completely?

feedback appreciated. TIA
Returners
1.8 / 5 (5) Jan 01, 2014
They've really got to get away from calling these planets "super earth's". The general public is going to think it's a huge Earth but it's not. If the planet's gravity would crush a human like an aluminum can or the planet is so close to it's host star that it's temp is well above the boiling point of water then it's not a "super earth".


I totally agree.

A "Super-Earth" should be something which is provably primarily terrestrial, like Mercury, Venus, Mars or Earth itself, but having mean temperatures below the boiling point of Water. We would then call a large terrestrial planet that is too hot a "Super Venus" as the convention seems to be on this site.

I don't think a "Water World", one where the entire planet is covered in tens, hundreds, or thousands of kilometers of water, should be considered a "Super Earth" even if the bulk of the mass is terrestrial.

I also think that it shouldn't be Super Earth if above a certain percent mass is gaseous.
Returners
1 / 5 (4) Jan 01, 2014
Less than a fraction of a percent of Earth's mass is atmosphere, and the same can be said even for Venus, so it would seem to me that anything above a few percent of the mass of a planet being gaseous should qualify it is being considered something other than a "Super Earth", regardless of surface temperature.

You would not be able to live on the surface of a 4 Earth mass object, or even a 1 Earth mass object, if a full percent of it's mass were in the atmosphere. You'd be crushed to a thin paste by the weight of the atmosphere, even if it was otherwise moderate temperatures and pleasant chemistry. In fact, Carbon Dioxide liquifies even at Venus pressures (if it were Earth temperatures), so there wouldn't be a solid surface even on such a planet, if 99% of of it's mass were rock and iron, and the other 1% "atmosphere". There'd be a CO2 ocean, or whatever other gases and liquids can form.

Nothing like that should be considered an "anything" Earth, never mind "Super Earth".
Returners
1 / 5 (4) Jan 01, 2014
Stumpy:

The planet is being observed during Transit, not Opposition, so it's actually light that passes through the atmosphere, not reflection.

There could be some sort of interference, or it could be that the planet is too far away, so like the spectra blur together and mask one another, but I'm not sure. I thought scientists had taken planetary spectra farther away already, but maybe I'm mistaken. I know they have for Stars, but stars tend to be more homogenous than Planets, and they're fairly predictable anyway.

A planet could be made of anything, but I think you still ought to be able to discern at least one element that you can definitely say exists there in significant quantity. It does seem a little odd.
GSwift7
5 / 5 (2) Jan 02, 2014
So far, lots of good clean comments and genuine interest in this thread. That's rare here. Cool stuff.

Okay, so in regard to why we call one planet terrestrial, one Neptune-like and another a gas giant: One word; Density. You're right about the possibility that there may be other types, but we don't yet have examples of anything that definitely falls outside the known types. There are observations that "may" indicate some planets that are so exotic as to fall into an entirely new type, but better observations might clear those up.

The term "super earth" is unfortunate, but oh well. Just use the term terrestrial or rocky and you'll get a lot less arguments started by people who don't really understand what you're talking about when you say "super earth". I think it's reasonable to assume the average reader will not understand what 'super earth' really means, so you'll get all kinds of confused questions and absurd remarks when you use it.
GSwift7
5 / 5 (2) Jan 02, 2014
In regard to not being able to see a chemical signature from the atmosphere:

The planet is being observed during Transit, not Opposition, so it's actually light that passes through the atmosphere, not reflection


IIRC, they are actually comparing the spectra of transits to the spectra of oppositions and subtracting the difference. That is how they attempt to eliminate the spectrum of the star from the data, as far as I know. Maybe someone could confirm/deny that?

Anyway, this will be a fun thing to talk about, if anyone else is game.

I believe there are a few different factors that can 'potentially' tell us something about the atmosphere of the planet. There's a couple of catches though. One big gotcha is in regard to the visible size of the planet from our point of view. In order to guess the albedo of the planet, we need to compare how much light it blocks in transit to how much it reflects in opposition. If our size estimate is off, then it throws the albedo off.
Q-Star
5 / 5 (1) Jan 02, 2014
In regard to not being able to see a chemical signature from the atmosphere:

The planet is being observed during Transit, not Opposition, so it's actually light that passes through the atmosphere, not reflection


IIRC, they are actually comparing the spectra of transits to the spectra of oppositions and subtracting the difference. That is how they attempt to eliminate the spectrum of the star from the data, as far as I know. Maybe someone could confirm/deny that?


Yeppers, ya are exactly correct. They are observing the spectra of both the transits and oppositions and comparing the data.
Q-Star
5 / 5 (3) Jan 02, 2014
The launch of NASA's next major space telescope, the 6.5m James Webb Space Telescope (JWST), later this decade should reveal more about such worlds, Kreidberg said. "Looking forward, JWST will be transformative," she said. "The new capabilities of this telescope will allow us to peer through the clouds on planets like GJ 1214b. But more than that, it may open the door to studies of Earth-like planets around nearby stars."


Just rubbing salt into the wound. Ya know for the price of ONE Iraq war we could have the JWST flying already,,,, with a moon base,,,,,, and a good start on a manned Mars mission.
GSwift7
5 / 5 (3) Jan 02, 2014
continued:

So, assuming the size/albedo is correct, the next step.

If the albedo is close to 1.0, then you can't really know anything about what the planet (or its atmosphere) is made of. It won't have any discernable spectrum in that case. Of course, this isn't the planet's true albedo, rather this is its albedo in the limited range of frequencies we are observing in, and also limited by the frequency output of its star (you can't reflect or absorb any frequency that the star didn't shine on it).

In the case of this particular planet, the albedo in those frequencies is so high, and the apparent size/mass of the planet is so large, that they are assuming reflective clouds. Keep in mind that if the atmosphere is 400 F, it could have metal vapor and all kinds of crazy precipitation cycles and chemical reactions going on. That's enough energy to do things that don't happen naturally anywhere in our solar system.
GSwift7
5 / 5 (2) Jan 02, 2014
Continued:

That brings you to another potential roadblock.

IF the planet does not have either too much or too little albedo, then you've got to be able to identify the fingerprints of the chemicals. There are countless possibilities, but we have a library containint some of them. So, you do statistical analysis of the frequency range your telescope can handle, you subtract the spectrum of the star and any other intervening materials, and you try to pick out a chemical fingerprint that you know.

Based on all of these factors, you try to play an elimination game, which really just narrows down a large-ish list of possibilities, and that's about it.
GSwift7
5 / 5 (2) Jan 03, 2014
speaking of exoplanets, I just read in National Geographic that Tatooine only has five years left.

The movie sets from episode 4 and the prequels were built in the Morocan desert. The episode 4 set is long gone, covered by dunes, and the newer set has a dune advancing on it now. They estimate it will be covered in five years.

Won't it be funny, in a few thousand years, when the movie is long forgotten, and some archeologists dig up those strange buildings? lol
Returners
1 / 5 (2) Jan 03, 2014
Won't it be funny, in a few thousand years, when the movie is long forgotten, and some archeologists dig up those strange buildings? lol


Ancient, Ancient Aliens: Episode 350.

"...even more intriguing, the anthropocenes appear to have had inter-stellar space flight. New evidence uncovered by archaeologist, Dr. Pyong, shows these strange domed structures, with odd literature and art displaying space ships and what appear to be melee weapons made of pure energy. Did our ancestors get this technology from the Anunaki?" *cut to commercial*.
Zephir_fan
Jan 03, 2014
This comment has been removed by a moderator.
Captain Stumpy
5 / 5 (1) Jan 05, 2014
Q-Star
GSwift7
Thanks for the lesson. I wondered how they would get spectra from the planet and separate it from the star.
I appreciate it.

Keep in mind that if the atmosphere is 400 F, it could have metal vapor and all kinds of crazy precipitation cycles and chemical reactions going on. That's enough energy to do things that don't happen naturally anywhere in our solar system.


@GSwift7
what about Venus? I thought Venus was hotter than that.
GSwift7
5 / 5 (1) Jan 06, 2014
what about Venus? I thought Venus was hotter than that


Yes, and Venus has almost 100 times the atmospheric pressure of Earth as well (chemical reactions depend on pressure as well as heat). Except for the pressure, Venus is a lot like Earth, but that one difference makes a huge impact.

Imagine an atmosphere 1000 times more dense than Earth's, or a million times. With enough pressure, you can have all kinds of things that might seem strange to us, such as things remaining liquid at 400 degrees, which we think of as a gas at room temperature. The dense atmosphere should also pick up and cary massive amounts of dust, even high into the atmosphere (we see this on Venus). As we know from Venus (and volcanos here on earth), dust in the atmosphere is a big factor too.

So, do you see how a hot super-earth is likely to be quite different than anything in our solar system? It might be just like Venus, but it's so different that we can't assume that.
Captain Stumpy
not rated yet Jan 06, 2014
So, do you see how a hot super-earth is likely to be quite different than anything in our solar system? It might be just like Venus, but it's so different that we can't assume that.


@GSwift7
i gotcha
thanks for clearing that up. i think i understand now...

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