Scientists: Oceans, clouds, rain possible on distant planet
A graphic shows surface temperature variations on Gliese 581d and how wind patterns would moderate the climate.
May 18th, 2011
10:57 AM ET

Scientists: Oceans, clouds, rain possible on distant planet

Astronomers in France say a rocky planet orbiting a star that's one of our closest galactic neighbors may have all the ingredients to make us earthlings feel right at home.

The planet Gliese 581d, orbiting the red dwarf star Gliese 581 about 20 light years from Earth, could support oceans, clouds and rainfall with a greenhouse effect that would moderate its temperatures, the team of scientists from the Institut Pierre Simon Laplace in Paris says in a study published this month in The Astrophysical Journal Letters.

If you're thinking  the Gliese 581 system and possibly habitable planets sound familiar, you're right. Just last year, scientists reported that another planet, Gliese 581g, was a prime candidate to support life.

More recent studies have cast doubt on whether Gliese 581g even exists, although one of the scientists who claimed its discovery, astronomer Steven Vogt of the University of California-Santa Cruz, has defended his work, according to a report on

With the 581g debate in mind, the scientists in Paris decided to take another look at 581d, which they note is seven times the size of Earth. When it was discovered in 2007, 581d was thought not to be capable of sustaining life, because it has permanent day and night sides, with the night side too cold for living organisms, and it gets only a third as much energy from its star as Earth gets from the sun.

The Paris scientists used a new atmospheric simulation model to look at 581d. And here's what they found, according to a press release:

"With a dense carbon dioxide atmosphere - a likely scenario on such a large planet - the climate of Gliese 581d is not only stable against collapse, but warm enough to have oceans, clouds and rainfall."

The fact that 581d orbits a red dwarf star makes a big difference, they found.

On Earth, a phenomenon called Rayleigh scattering reflects heat from our sun in the form of blue light back into space. This helps keep Earth from overheating. But as the atmosphere on 581d is absorbing only red light, Rayleigh scattering doesn't come into play.

"This means that (light) can penetrate much deeper into the atmosphere, where it heats the planet effectively due to the greenhouse effect of the CO2 atmosphere," the scientists said in the press release.

Their model also showed "the daylight heating was efficiently redistributed across the planet by the atmosphere, preventing atmospheric collapse on the night side or at the poles," they said.

But don't pack up the spaceship just yet.

"While Gliese 581d may be habitable there are other possibilities; it could have kept some atmospheric hydrogen, like Uranus and Neptune, or the fierce wind from its star during its infancy could even have torn its atmosphere away entirely," the scientists said.

And even if you left now, in a current-technology spaceship, it would take 300,000 years to get to the Gliese system.

So there's plenty of time to figure it out. Or get Capt. James T. Kirk and the starship Enterprise to explore strange new worlds.

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Filed under: Space
soundoff (364 Responses)
  1. Chris

    LOL 20 light years away. Better not pack your bags folks.....even if we came up with a light speed engine it would still be to slow.

    May 18, 2011 at 11:56 am | Report abuse |
    • stu

      I don't think so. A light year speed engine would take 20 years to get there. We currently have a probe going to the "planet" Pluto which is a 15 year trip. I think/hope one day in the VERY distant future we would have the technology, to at least send an unmanned probe to check out these planets or others that are similar to them a bit closer.

      May 18, 2011 at 12:25 pm | Report abuse |
    • Typinator

      I think an "ark" spaceship with some adventurous souls using current technology could be sent toward the system with the anticipation that technology on earth would reach "Star Trek" velocities within a few hundred years. Thus only a few generations would pass on the ark before a star ship from Earth would show up and take them the rest of the way in no time at all. Of course, then it would seem pointless to send out the ark in the first place... if only for the adventure.

      May 18, 2011 at 12:47 pm | Report abuse |
    • Dan

      Time dilation aboard a near-light speed vessel would reduce personal aging for the travelers, but Earth time would pass as usual, so the astronauts would be chronologically younger than their peers on Earth when they got there.

      May 18, 2011 at 12:47 pm | Report abuse |
    • dissenter

      @stu, humans are going to outgrow and destroy our planet long before that's even a possibility.

      2 words... cryogenic hibernation. If we can figure that out then we could easily send people out on a mission. Create in essence and unmanned probe ship (that needs no interaction from a human), and fill it with cryogenically hibernating scientists and researchers. Set the timer for 300,000 years and voila! Set it and forget it. lol I understand it's pretty far fetched but hey, so is the idea of travelling at light speed.

      May 21, 2011 at 8:50 pm | Report abuse |
  2. Scottish Mamal

    I like to go beyond no ass has been

    May 18, 2011 at 11:56 am | Report abuse |
    • Jess

      Tried to be clever and screwed that up.

      May 18, 2011 at 12:06 pm | Report abuse |
  3. BB

    Who cares? It's a planet nobody will visit, a planet that can't even be even imaged. This is not news. CNN, stop posting this boring, useless exoplanet articles. You might as well report on every new star that is found.

    May 18, 2011 at 11:57 am | Report abuse |
    • KristinaKaye

      I care!

      May 18, 2011 at 12:03 pm | Report abuse |
    • wzrd1

      So, science news is bad? I guess you'd prefer biblical verses instead?
      Knowledge is EVIL, huh?
      If you don't want to read about it, don't select the link, idiot.

      May 18, 2011 at 12:12 pm | Report abuse |
    • j

      I care too. This is fascinating.

      May 18, 2011 at 12:21 pm | Report abuse |
    • Pixelologist

      Hey, practicality is good. No doubt. But so is curiosity and a thirst for knowledge – these are qualities that have allowed humans to progress as far as we have and will hopefully allow us to continue progressing. Don't be needlessly provincial. There's room for all types of research.

      May 18, 2011 at 12:22 pm | Report abuse |
    • T3chsupport

      Just like those retards who thought they could sail around the world! I bet they're regretting that now that they're so close to the edge!

      May 18, 2011 at 12:24 pm | Report abuse |
    • WordBearer

      Right Now. Can not be reached Right Now: meaning today. We might have a way of reaching it next week.

      May 18, 2011 at 12:26 pm | Report abuse |
    • AlsoCare

      On the contrary, this is the first news in over a week that have been interested in. It is much more interesting than Arnold and Maria.

      May 18, 2011 at 12:30 pm | Report abuse |
    • Neal Kelley

      I care also... I guess you think the world going to end on May 21 also!!!!

      May 18, 2011 at 12:43 pm | Report abuse |
    • Roberto Vidal-Garcia

      You're an ignorant idiot. Fining life on other planets would have a very profound change in how we see life in this planet. Finding a planet with the possibility of life IS news for most people with the slightest hint of an imagination.

      May 18, 2011 at 1:44 pm | Report abuse |
  4. Wolverine

    With a planet 7 times the size of the Earth the gravity would be crushing. Maybe simple virus/bacteria/slime mold and some ocean plankton, not much else it would seem. This is a long, long shot.

    May 18, 2011 at 11:57 am | Report abuse |
    • KristinaKaye

      Just imagine where our civilization will be in 1000 years from now. I bet within that time we develope the technology to travel the universe at fantastic warp speeds! I do!

      May 18, 2011 at 12:06 pm | Report abuse |
    • whatever

      7 times the size doesn't mean 7 times the mass. Twice the mass, and 7 times the size, would have less than 2.0 G's on its surface.

      May 18, 2011 at 12:34 pm | Report abuse |
    • James

      You may also want to note that just because it wouldn't sustain the types of life that have developed on earth does NOT mean that it hasn't spawned it's own types of life that are tailored to it's own conditions.

      Life doesn't have to evolve the exact same way it does here.

      May 18, 2011 at 12:42 pm | Report abuse |
    • Seattle Dad

      Seven times the size of Earth does not necessarily mean seven times the mass of earth. I would presume that this comparative was volumetric.

      May 18, 2011 at 12:43 pm | Report abuse |
  5. Scottish Mamal

    I can suc faster than speed of light

    May 18, 2011 at 11:58 am | Report abuse |
    • KristinaKaye

      I'm sure you can!

      May 18, 2011 at 12:15 pm | Report abuse |
    • Neal Kelley

      Suck on this!!! lol

      May 18, 2011 at 12:44 pm | Report abuse |
  6. ptl

    God is not a Ferrie Tale. Someday, "Every knee will bow and every tongue will confess that Jesus is Lord." Even yours.

    May 18, 2011 at 12:05 pm | Report abuse |
    • ron

      freedom of religion means freedom from religion. keep your delusions to yourself.

      May 18, 2011 at 12:11 pm | Report abuse |
    • Cedar Rapids

      quoting from a book that promotes your religion is not exactly an unbiased citation source.

      May 18, 2011 at 12:11 pm | Report abuse |
    • YoDufus

      Another delutionist who thinks that jebus is his savior. Yeah, that makes a lot of sense! What about scientology, does that make sense to you too? What about the book of mor(m)on? There's just as much sense there as your book. The stupid delutionists, under the guise of "freedom of religion", have accepted this lunacy. Maybe we should be looking for all of those worlds in our corner of the galaxy that L Ron HeadUpAss wrote about in our early human history, eh?

      May 18, 2011 at 12:23 pm | Report abuse |
    • Nah

      ron: "freedom of religion means freedom from religion. keep your delusions to yourself."

      You do realize this is meaningless and self defeating, right?

      What does "freedom from religion" even mean? That people have a right to practice religion and worship how they choose, but you have a concurrent right to silence them or prevent them from acting religiously? Because it offends you and you don't want to see it or hear it?

      That's brilliant.

      You might want to think about soundbites before regurgitating them.

      May 18, 2011 at 12:28 pm | Report abuse |
    • Nah

      yofus: "The stupid delutionists, under the guise of "freedom of religion", have accepted this lunacy."

      It's nice to see bigotry take an acceptable, modern form. Namely in the guise of militant atheism.

      Are you going to start burning Bibles and religious worshippers at the stake?

      May 18, 2011 at 12:30 pm | Report abuse |
    • SpaceCadet

      Your an idiot. Learn how to spell.

      May 18, 2011 at 12:41 pm | Report abuse |
    • YoDufus

      So Nah, you're OK with scientology and latter day saints? There's nothing wrong with that to you? What about islame? Ok with that? Have you ever taken the time to learn anything about those delusions? There the same as your delusion, they're false. If you think we're going to just sit around while you delusionists rant and rave, and destroy the world, you're even more delusional than we thought.

      May 18, 2011 at 12:42 pm | Report abuse |
    • Seraphim0


      I find it outright hilarious that you bring up these possible atrocities that a militant atheist might perpetrate... and they are the very atrocities christianity has commited in the past. Barbaric, right? Highly disturbed? Full circle, some might say. Though, I wouldn't care to do any such thing, myself... I find it funny that you bring these terrible things up as a sign of his monstrosity when christianity did them on a regular basis. Burning at the stake... burning books they do not agree with- not saying this is in practice today, but it was in the past.

      May 18, 2011 at 12:43 pm | Report abuse |
    • YoDufus

      "Are you going to start burning Bibles and religious worshippers at the stake?" No need, although there is nothing wrong with burning bibles, since you people burn other religions and scientific books all the time. Nope. It's called REJECTION. Every time it comes up, it's rejected. Any time it's argued in favor of, it's rejected by Reason Any business that promotes delusion is not patronized. Any people that promote delusion are ridiculed and rejected. Eventually, like a weed that that's been poisoned, it will whither away and die, all on it's own.

      May 18, 2011 at 12:53 pm | Report abuse |
    • fimeilleur

      @ nah.
      Freedom FROM religion means just that: I have the right to live MY life without you trying to force YOUR unfounded, unsupported, untested beliefs on me. (ie the right of a woman to choose to have her fetus aborted, the right of scientists to collect and study stem cells in the search for cures of horrific, painfull diseases, the right of a terminally ill person to choose to die in dignaty by his/her own choosing) Prove to the world that YOUR God exists, and we will consider His stance on these and other matters.

      May 18, 2011 at 1:04 pm | Report abuse |
    • ejes

      Jesus promised the end of all wicked people. Odin promised the end of all ice giants. I don't see any ice giants around.

      Odin is the true god.

      May 18, 2011 at 1:57 pm | Report abuse |
    • Nah

      seraphim: "I find it outright hilarious that you bring up these possible atrocities that a militant atheist might perpetrate... and they are the very atrocities christianity has commited in the past. Barbaric, right?"

      Yes ma'am.

      He wants to burn Bibles and hopes the religious die. Just because his barbaric tendencies are a product of his atheism doesn't vindicate them.

      Good job?

      May 18, 2011 at 2:42 pm | Report abuse |
    • fimeilleur

      @ nah,
      "He wants to burn Bibles and hopes the religious die. Just because his barbaric tendencies are a product of his atheism doesn't vindicate them."

      You're the one who introduced Bible burning into the conversation... not him (her)... You basically projected your desires on someone else and called it proof... says more about your character than anyone else's.

      May 18, 2011 at 5:22 pm | Report abuse |
  7. ken

    If we send a generational ship (most likely scenario as the technology to travel will undoubtedly start with one of these vessels) the generational ship will arrive after we are already colonizing the place because by the time they get there we will have invented better engines by which to travel to the planet. However, the generational ship will be best suited to terraforming people to the conditions of the planet itself. With artificial gravity being a must for any spaceship, we would be able to amp up the gravity with each new generation (yes a breeding program and control over how many people are born and when will be important). With gravity being increased for each generation born on the ship, by the time they arrive on the planet, the planet's gravity and atmosphere wont be an issue. yes the ship could be programmed to simulate the atmosphere on the planet to better acclimate the future colonists. interesting to think about.

    May 18, 2011 at 12:05 pm | Report abuse |
    • KristinaKaye

      Great idea Star Gazer ... I would go!!!

      May 18, 2011 at 12:10 pm | Report abuse |
  8. Star Gazer

    Astronomers in France have been binge drinking again. This news has as much relevance as another of the million stars that have been discovered.

    A planet 7 times the size of the Earth and 20 light years away! WHO CARES?! Their inhabitants are not coming to visit us and we won't be visiting them!!!

    May 18, 2011 at 12:10 pm | Report abuse |
    • KristinaKaye

      That's really thinking on the positive side. Do you have any great ideas at all?

      May 18, 2011 at 12:12 pm | Report abuse |
    • Cedar Rapids

      'Their inhabitants are not coming to visit us and we won't be visiting them!!!'

      But now we know its there.

      May 18, 2011 at 12:12 pm | Report abuse |
    • wzrd1

      That we won't be visiting means that we should not study and learn? Or are you forbidding my grandchildren and their children from going too?
      Or is it that science and knowledge is evil?
      Personally, *I* care. But then, MY mind isn't as highly limited than yours is. Were humans to have thought as you think, we'd still be starving in Africa, not caring what was over the horizon.

      May 18, 2011 at 12:16 pm | Report abuse |
    • Cedar Rapids

      'Were humans to have thought as you think, we'd still be starving in Africa, not caring what was over the horizon.'

      Though to be fair wzrd1, you do have to wonder which ancestor the Inuits have to blame for arriving in a frozen tundra that would result in an amazingly hard life and thought....'ah perfect, lets pitch camp here.' I can imagine all his friends going, 'what on earth? really? we passed forests and praires teeming with wildlife and you want to stop here? are you mental?'

      May 18, 2011 at 12:22 pm | Report abuse |
    • ejes

      just because you're too small and stupid to know what this means to the scientific community, doesn't mean that the rest of us aren't interested.

      if people like you were in charge we wouldn't have progressed since the 1500's!!!!!

      May 18, 2011 at 2:00 pm | Report abuse |
  9. Shano

    Its amazing that we have found the basic ingredients for life on so many bodies so close to earth. Consider the frozen oceans of Mars and the recently discovered water vapor on Io (a moon of Jupiter). These are located on our front steps, relative to the size of the known universe. Now, with yet another near-by planet potentially capable of life, people need to believe that in all likelihood the known universe holds a vast amount of life beyond our world.

    May 18, 2011 at 12:10 pm | Report abuse |
    • KristinaKaye

      Hooray! Something intelligent has been said! I agree again!

      May 18, 2011 at 12:13 pm | Report abuse |
  10. davidk

    we could go there. we've got the technology from the roswell crash!

    May 18, 2011 at 12:20 pm | Report abuse |
  11. lauradet

    All I know is that mankind needs to stay right here on Earth. No need to spread mankind's greedy evil ways.

    May 18, 2011 at 12:21 pm | Report abuse |
    • fimeilleur

      I think what really bothers you is that your God must not have created this planet, Earth, specially for our habitation... the more planets He supposedly created, the less special this one really becomes... OR, is it that science is proving more and more, day in and day out, the your God is quite irrelevant?

      Now, I only assume you are religious because of your use of the word Evil... no rational human being thinks of mankind as inherantly evil...

      May 18, 2011 at 1:16 pm | Report abuse |
  12. Marie MD

    Very interesting story if you think that only our "kind" can live in the same environment that we need go survive.
    There could probably be other minor species in other planets. Let's send someone from AK to check it out. The sooner the better since it will take so long to arrive!

    May 18, 2011 at 12:29 pm | Report abuse |
  13. stanton


    May 18, 2011 at 12:32 pm | Report abuse |
  14. Wolf

    Light speed travel wouldn't be the biggest logistical problem. Getting there in 20 years isn't a long time (i.e. it's manageable), assuming the ships have advanced life support. The biggest logistical problem, even with an unmanned probe, would be communication. Even if we could send an unmanned probe to this planet, it would take 20 years for us to send signals to it (unless we find some way to communicate outside of the EM spectrum – faster than light, not at the speed of light) and another 20 years for it to send signals back. In other words, even the simplest commands to the craft would take 40 years to accomplish.

    May 18, 2011 at 12:39 pm | Report abuse |
    • Seraphim0

      We could tap into tachyon waves. That way we can get the messages before we even send the craft. Woo. Kidding, of course.

      May 18, 2011 at 12:45 pm | Report abuse |
    • fimeilleur

      @ wolf,

      Small problem with your math... the correction would happen in 20 years... we would only learn about the success or failure of the correction 20 years later... but you're right about the problem being communication with the craft... imagine the distance travelled if the craft reports a tradjectory error, 20 years later, we find out about it and send an emmediate correction that it would receive in 20 years... current speed cappabilities... we're looking at the approximate width of our solar system worth of distance travelled without even knowing if our corrections arrived in time or were effective. Blows the mind.

      May 18, 2011 at 1:25 pm | Report abuse |
    • Realist

      You're thinking linearly. Quantum transference/entanglement could be used as a way to execute command and signals. These types of events are simoultaneous no matter how great or small the distance. Experiments with entanglement are reproduceable, it's only a matter of time before humanity finds a way to harness this natural behavior.

      If we are to ever acheive near light speeds, one must presume that FTL communication would be one of the most important aspects of the research well before humans travel in such a manner.

      May 19, 2011 at 9:39 am | Report abuse |
    • fimeilleur

      Very interesting. Something to consider and research. I don't have enough knowledge in the matter but it's interesting. Thanks for posting.

      May 20, 2011 at 4:52 pm | Report abuse |
  15. Jeremy

    This planet is not as out of reach as it may seem. I think the 100k they quoted is based on a chemical rocket for entry into orbit then some sort of electrical engine for the trip to the star (PPT perhaps?). This is absolutely the wrong technology for this mission. IF the material issues can be revolved a matter/anti-matter anhilation engine should be able to make that trip in a fraction of the time. Estimate 50-60 years of travel and then 20 years to send a signal back at the speed of light. Granted we cannot get info back in the scope of a single person's scientific career but we could send a mission to gather data for use by the next generation of planetary scientists.

    The main issue to work out on matter/anti-matter engines is the heat. They burn so hot we cannot build materials that can withstand it. This is helped by making the nozzle purely magnetic. Essentially you use super magnets to force charged particles into a converging/diverging nozzle. This also requires a substantial power source on board (nuclear) that is technical illegal to operate in space right now.

    May 18, 2011 at 12:40 pm | Report abuse |
    • Jeremy

      This is a comment on Wolf's post about communication issues on the mission of this distance.

      Quantum entanglement may be a good way to get around the communications issue. This would also reduce the time it would take to return data from a mission like this.

      May 18, 2011 at 12:43 pm | Report abuse |
    • Wolf

      Yeah, Jeremy – It's well thought out, but we still don't know enough about quantum science to use it as an effective means of communication. That's definitely something we should be studying, though – if we had that capability, we'd be able to communicate with the Voyager probes in minutes instead of days (of course, they don't – and never will – have the necessary equipment aboard; I was just speaking hypothetically).

      As for your other point, I don't think they were referring to chemical rockets – I think they were talking about ships with ion drives; we do have ships like that.

      May 18, 2011 at 12:51 pm | Report abuse |
    • Jeremy

      Yes I think they are basing it off of an ion drive of some type. Chemical rocket or even nuclear thermal would be even worse for this mission. You are looking at 700ish seconds of ISP even with a nuclear thermal, chem rockets top out at like 450 ISP. This mission requires something in the hundreds of thousands ISP which is out of the scope for most ion drives as well.

      May 18, 2011 at 2:26 pm | Report abuse |
    • Jeremy

      More properly delta V describes the mission, but I think you understand what I am getting at. The engine selection for this mission would need hundreds of thousands seconds of ISP.

      May 18, 2011 at 2:29 pm | Report abuse |
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