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. George Patton

    I simply love how every scientific article, EVERY SINGLE ONE, turns into a debate about religion. I simply love it!

    No, I don't.

    I HATE IT!!!!!!!!

    May 19, 2011 at 3:29 pm | Report abuse |
  2. George Patton


    Apparently, English isn't the one you WRITE best in. Example: what=watt?

    May 19, 2011 at 3:31 pm | Report abuse |
    • seppe

      @George patton,To be honest with you,i do make mistakes,and i also check the spelling with the (edit feature of my macbookpro)(which i paid 2500 us dollar) i assume that the computer it is not as smart as you,sorry about that,but few thing i must say,i don't appreciate you talking down to me ,if i am not good enough for you,the feeling is mutual.

      May 20, 2011 at 2:18 pm | Report abuse |
  3. ptl

    Spiritual warfare is increasing in these last days. Satan is doing his best to malign God's word. If one truly humbles their heart and asks God to reveal Himself, He will. Approximately 80 per cent of Biblicle prophesy has been fullfilled, in every detail. The last part is being fullfilled daily. The world is not ending on the 21st and no one can know when it is. We can however, recognize the signs of it getting nearer to the time of Christ's return. The scoffers and God haters and the blatant hostility toward Jesus and Christianity, is just more prophesy being fullfilled. Mankind thinks they are superior in intelligence, but "mankinds intelligence is foolishness to God."

    May 19, 2011 at 3:35 pm | Report abuse |
    • fimeilleur

      Satan doesn't have to do very much to malign God's word... "God" did a pretty good job of it himself. You complain about context... what context is it acceptable for a man to offer his daughter and concubine to be r-aped by a mob? (JUDGES 19:22-29) What context is it acceptable for a man to kill every man, woman, child, cattle in a village and then loot the village for it's spoils? (Deuteronomy 3:6 and MANY other examples of this morally correct act). Yeah, you better Praise the Lord... or else...

      May 19, 2011 at 7:32 pm | Report abuse |
    • Joseph Bleaux

      People, you included, need to stop believing in invisible supernatural beings in the sky and under the ground. You live in a fantasy world. If you want to wallow in your fairytale world then that's your right. Just stop trying to push that ignorant nonsense on everyone else.

      May 22, 2011 at 7:49 am | Report abuse |
  4. ptl

    @ filiemeur Your scripture bashing proves nothing other than you've made a career of taking it out of context and never took the time to truly STUDY it to find out what it actually IS saying. You've spent 2 days on this site flapping your yap at everyone that disagrees with your darwinian dribble. Get a life, stop hating, to each his own.

    May 19, 2011 at 5:04 pm | Report abuse |
    • fimeilleur

      How is any of the contradictions taken out of context? Each line is an independant statement of "truth". It's not hard... show me where context would be involve.,,

      Here's why I fight (and continue to fight) religion at every opportunity: Your type continuously tries to push your unfounded dogma of supposed morality on society as a whole (cont-raception, abo-rtion, stem cell research, same se-x marriage, euthonasia, etc). Stay out of MY rights and freedoms, and I'll reciprocate. But when you prevent doctors and scientists from advancing human knowledge based on the presumption that it offends your God, prevent 2 concenting adults from actions in the privacy of their own home because it offends your God, prevent the terminally ill from dying in dignity because it offends your God... Prove your God's existance and we'll consider his opinions. So far, you have a claim that the Bible is the "word of God" and it is true because God said so. Well, this god of yours can't keep his own story straight... he loses a lot of credibility there.

      May 19, 2011 at 7:18 pm | Report abuse |
    • dissenter

      I have to admit, ptl, he does have a point. Didn't 'God' give man free will? Yet 'Gods' followers continue to try and take that free will away. I don't know if 'God' exists, and neither do you, and neither of us will know until death. You can have faith that he does, which is the point of religion, but I am of the understanding that 'God' did not want his words to be forced upon anyone. Let people be as they are, if 'God' exists, he will be the judge of people when they pass.

      Now I ask, why are you two discussing this instead of discussing the scientific discovery of a possible life sustaining planet that this article is actually about? I'm pretty sure there are many other RELIGION forums on which you can have your argument.

      May 21, 2011 at 8:27 pm | Report abuse |
    • Mance Lotter

      @fimeillieur – the only way you can prove God doesn't exist is to say that not only have you searched every corner of the universe but also that you have searched every corner of the universe at the same time lest He move to a place you already searched to avoid being found. In essence, you have to be omnipresent, like God, to KNOW God doesn't exist. Otherwise, all you have is faith and belief that God doesn't exist, which makes you and any true follower of any religion basically the same. That makes you a closet religaphobe.

      May 21, 2011 at 9:09 pm | Report abuse |
    • Andrew

      Mance Lotter, would you then argue he can't claim he doesn't know unicorns don't exist? That we only have faith unicorns don't exist? Would that make unicorn-denialism a religion by your standards?

      May 21, 2011 at 9:25 pm | Report abuse |
    • Brian Hartman

      Mance Lotter:

      It's not impossible to prove that God doesn't exist without being omnipresent or omniscient. The God of the Bible (at least, the Christian variety) is *existentially* impossible. To put it simply: I don't have to search the entire universe at once to prove that square circles don't exist. The very description of what "God" is, according to Christian dogma (starting with Jesus being God and separate from God at the same time) is what proves God's inexistence.

      May 21, 2011 at 9:50 pm | Report abuse |
    • skywalker

      It is impossible to prove there is a God, but it is also impossible to prove that a God doesnt exist. I consider myself as a believer in a higher being. I do not use the bible to prove the existence of a God but science itself. I ask any non believer to give me what are the possibilities that one planet in this solar system has the perfect attributes to contain life as we know it. We have searched our planet and we have found life to exist in the coldest, hottest, darkest, and even places where the sun's light does not penetrate. But when we look at any other planet or moon we can not seem to find any life. Is this just dumb luck? that upon the Bing Bang a rocky planet on the outer rim of the Milky Way galaxy was placed just at the right place? From what I understand i have a better chance of hitting the lottery everyday for the next year than that process to happen just by pure luck.
      For anyone that believes that religion is the cause of any harm being done to anyone they should check their sources. From what I understand one of the most important messages that Jesus preached was to love one another. In Mathew he even goes as far as to say that it is not enough to love the ones that love you because that is easy, he goes on to say it more important to love the ones that done love you!!!! Where in that does anyone get that religion caused any harm to anyone? The Quran again if you read it, never states to hurt anyone, it goes as far as to say to be understanding of the people that do not agree with what Muslims believe in. What happens though is that when humans get involved that make up things to suit them and then the killings happen. It is not religion it is the people that we elect as leaders and then follow like sheep that cause all this.
      I also can not tell you what will please God. I personally believe that God has given us all the gift of free will. That means for me to do as we please and enjoy life. So if God has given us the power of free will then he will be the sole judge when it comes that time to be judged. For anyone that believes that being gay, or conducting stem cell research is against Gods will, trust me if it was something God did not want to happen and he is as all powerful as we believe he is, he would stop it. God is the architect of all, even the people of things that we believe are evil. So if we do believe that God is just and he gave us free will, let us explore the whole universe. If He did not want us to explore it He woudnt have made it.

      May 21, 2011 at 10:18 pm | Report abuse |
    • Andrew

      Skywalker, you're the classic example of tailoring facts to fit your argument, rather than letting facts build your concept.

      Consider, for a moment, that the earth didn't have the "perfect attributes to contain life as we know it". Then life wouldn't exist on earth. But consider a rock not just in the milky way, but a rock ANYWHERE in the universe that has the 'perfect attributes to contain life as we know it'. Maybe there's one in the Andromeda Galaxy. Maybe one in the Whirlpool Galaxy. If one of those rocks had the 'perfect attributes to support life', it's eminently possible life would have evolved there. We'd then have the same discussion on an entirely different planet. Your problem is you a-sume that it is either earth or nowhere, and then say "what are the odds that it'd happen on this planet?" Well, same as on any other planet, probably very low, maybe so low that it happens only one every galaxy. But that doesn't mean that life had to evolve on earth, because if it happened on another planet in the milky way, we'd say the same things about an entirely different planet.

      The chances that life would evolve on this particular planet are pretty slim, but the chances that some planet somewhere will have life is not necessarily so slim. Or, better yet, consider a rock outside your room. The chance that it has that particular configuration is so astoundingly small that your lottery example seems like a very likely phenomenon in comparison. But SOME configuration was probable, so there's no reason why that particular configuration was so important. Thus, a rock outside your room will have a particular configuration out of an unfathomably large number of other potentials. Same with the earth, you need to stop a-suming that life was supposed to evolve here in particular.

      May 22, 2011 at 1:25 am | Report abuse |
  5. jim

    @steve, that was too funny, mostly because it's so true.

    May 19, 2011 at 6:35 pm | Report abuse |
  6. jim

    Want proof. If there is a God then something had to create God. If something created God then the something that created God would be God, so on and so forth. Now prove there is a God and that nothing created God. Without using a book written by humans.

    May 19, 2011 at 6:43 pm | Report abuse |
    • gabe

      Try wikipedia it can be quite enlightening sometimes.

      May 21, 2011 at 10:11 pm | Report abuse |
  7. Friendly Alien

    @ A. GARABAS credit where credit is due. The general "good word" of the scriptures are indeed positive. But the concept as a whole is no longer valid to the extent where the divide between people is so big that; I don't know you, you are perhaps on the other side of the world, we have never seen each other yet we are in conflict. As you know this is the world we live in today in 2011. That is the problem I have with religions in general not with the "good intentions" to live life in certain way.

    I'll say it again to stay relevant. Cool planet. I hope they do find an atmosphere that will be very exciting.

    May 19, 2011 at 7:21 pm | Report abuse |
  8. Doug Fitzgerald

    Religion has through history only been a breaking force when it comes to technological advancement. We would probably been a hundred years further in development if it wouldn't have existed. I can honestly not believe how people can encourage each other to support a belief of sorts that though history is responsible for hundreds of millions of lives slaughtered, burned to the cross or sent to their other most unpleasant deaths. I would without hesitation compare all killings in the name of faith similar to the Holocaust, the Gulag, Khmer rouge or any other massmurdering process... The only evil on this earth is evil itself and it comes in the form of believers believing in the righteousness of ther own faith.
    Some say that 95% of the earths population believes in some sort of higher being. The question I often get is: – "Are all those people wrong?" My awner is usually: – "Yes, they are wrong, probably mentally delusional and/or very easily effected by false clergy men and their non-sence jibberisch."

    Religious people, when your "God" gives you nothing please get sane and believe in Apple instead...

    May 19, 2011 at 8:10 pm | Report abuse |
  9. Doug Fitzgerald

    I said the same thing to someone I met and he replied: – "Give some proof that he DOESN'T exist"... Thts just rediculous... Thats like trying to find proof for a value of zero...

    May 19, 2011 at 8:21 pm | Report abuse |
  10. jason

    people are slowly awakening to the idea of just cherishing nature and the universe that we live in . and when we finally realize we don't have to worship the supernatural but can just find beauty in the world around us we will all be better off

    May 21, 2011 at 8:31 pm | Report abuse |
  11. Ed Galbraith

    Newsjoke is exactly right. The "god" writers of the bible (old and new) were largely ignorant of almost everything beyond their desert surroundings, afraid of anything unexplained and determined (like all religious zealots) to bring reason, and those who applied reason, to heel. Such a sad story. It's a matter of laying aside the things of your childhood when you are no longer a child.

    May 21, 2011 at 8:48 pm | Report abuse |
    • Mance Lotter

      so you're an atheist zealot or religaphobe who is intolerant of the beliefs and views of others all while probably calling yourself an open-minded progressive, acceptable of all people. ever notice how your circle of friends thinks much the way you do? but you only think you're so diverse because they LOOK different. diversity of thought is not an option for your kind! i think your kind bothers me way more than the over-animated religious nutjobs!

      May 21, 2011 at 9:23 pm | Report abuse |
  12. Bob from NY

    Wow a real science article on CNN instead of a "tech" article about apple products. Kudos to you cnn!

    May 21, 2011 at 8:53 pm | Report abuse |
  13. Ed Galbraith

    Nicely said, Sand. I'll pass on your "heaven" comment.

    May 21, 2011 at 8:54 pm | Report abuse |
  14. jakob

    Can't anyone just think this is cool without getting into a theological debate?

    May 21, 2011 at 9:06 pm | Report abuse |
  15. Mance Lotter

    regardless of whether or not there is life on this planet, one thing is for sure, we have caused it's climate to change – buy a hybrid – save Gliese 581d!!!

    May 21, 2011 at 9:18 pm | Report abuse |
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