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Microlensing Uncovers Earth-Like Planet

smooth wombat writes "Using a new technique called gravitational microlensing, a team of astronomers have discovered the smallest Earth-like planet circling a star 20,000 light years away in the constellation Sagittarius. Unfortunately the planet takes ten years to circle the red dwarf and has a surface temperature estimated at -220 C which means it's just a larger version of Pluto so the chance of finding life on this planet is essentially zero."

31 of 263 comments (clear)

  1. Wait... by scolby · · Score: 4, Insightful

    Unfortunately the planet takes ten years to circle the red dwarf and has a surface temperature estimated at -220 C which means it's just a larger version of Pluto so the chance of finding life on this planet is essentially zero.
    So it's earth-like how?

    1. Re:Wait... by Alotau · · Score: 4, Insightful

      From the article:
      "This is the most Earth-like planet we have discovered to date, in terms of its mass and the distance from its parent star," he told BBC News. "Most of the other planets that have been discovered are either much more massive, much hotter or both."

      He is an astronomer, so when saying it was Earth-like he was, of course, speaking relatively.

    2. Re:Wait... by mrsev · · Score: 5, Insightful

      "at -220 C .......so the chance of finding life on this planet is essentially zero."

      I get fed up with people saying this. Our data set for planets that can support life is 1. We have no idea what "other" lifeforms can survive. Pretty much everywhere we look on earth we find life.

      We find it at +120C at several thousand atmospheres of pressure next to thermal vents.

      We find it at -40 C under meters of ice.

      We find it living in our stomachs at a pH of less than 2.0.

      We find it making a living from cleaning the insides of a sharks mouth.

      I am sure that if you go into the charred remains of Reactor core number 4 chernobyl you will find plenty of life.

      All you need for life is some form of energy that can be harnessed and some raw materials to use. There is no justification for saying that we should look for life at 300 kelvin and 1 atmoshphere pressure and 20% oxygen. For the report on a "scientific" article it is just lame speculation dressed as informed fact.

    3. Re:Wait... by DerekLyons · · Score: 4, Informative
      Who is to say that there isn't intelligent life in the form of a vapor, or a thinking rock somewhere in the universe? [...] I hate to use a middle manager term, but what we need is a paradigm shift. To assume intelligent life would warm blooded and bipedal may be a mistake. Who knows what forms are out there?
      Nobody is assuming that intelligent life would be warmblooded and bipedal. In fact, nobody said anything about intelligent life in the first place, just that there was little likelihood of this planet harboring life.

      That being said, life depends on a certain level of chemical activity (I.E no thinking rocks) and a large degree of predictable organization (I.E. no intelligent vapor). Anything else requires repealing the laws of physics and chemistry as they currently understood. (The former is possible on the cosmic and subatomic scale, I.E. outside the realms of life. The latter is unlikely in the extreme.)

    4. Re:Wait... by birge · · Score: 4, Insightful

      well, you generally don't find complex life at temperatures where water and most (all?) hydrocarbons freeze, do you? i'm sorry you're 'fed up' with this kind of rampant speculation, but given that life anywhere will still have to obey the same physics, it's unlikely we'll find complex life at temperatures where little chemical activity takes place, and where pretty much everything is solid.

    5. Re:Wait... by Nazmun · · Score: 4, Interesting

      I'd agree with you on needing so called perfectly earthlike conditions for life but... -220c is cutting it...

      It's so close to absolute zero that most chemical reactions dont' happen there. The chance of life forming is probably next to nothing.

      --
      Hmmm... Pie...
    6. Re:Wait... by jc42 · · Score: 5, Interesting

      How do we know there aren't certain forms of life for which -220C is like a warm, hunky-dory bath?

      Actually, there are some good (but not conclusive) chemical reasons. Some of them came out in the recent discussions of why Titan might support life.

      Now, -220C is abut 53K, which is pretty cold. Titan is about 94K, which doesn't sound much warmer to us, but it's actually nearly twice as "warm". At 94K, methane is a liquid, and it's also a solvent. It behaves much like water, though it's a non-polar molecule, so any biochemistry would be different from ours. In particular, methane is good at dissolving organic (i.e., carbon-chain based) compounds.

      At 53K, methane is a solid.

      All this is significant because it's reasonable to assume that complex life requires complex chemistry. At low temperatures, the only way known to do this is with carbon chains (though there has been speculation that at higher temperatures than ours, silicon could perform a similar role). And for biochemistry to work, most of the biochemicals should be in a liquid matrix, so they can move around and interact easily.

      So a planet at 53K wouldn't be a very likely place to find complex chemicals with compex interactions. Everything interesting would be solid. At 94K, it's possible, with methane as the solvent substrate. At our body temperature, 310K, methane is a gas, but water is a liquid and a good solvent, so biochemistry works for us.

      But you're right that this is all speculation, based on the only kind of life that we know. Science-fiction writers have contemplated life at other temperatures, but we have yet to find evidence of any.

      A few years back, Robert Forward wrote a sci-fi novel, Camelot 30K, which is about the discovery of life on a Pluto-like planet in the Kuiper belt. The title comes from its ambient temperature, 30K, and the social order which is medieval. Being a good physicist, he explains at one point that the living creatures are all "warm blooded", with body temperatures arund 90K. This is so that their body fluids remain liquid. It turns out that they inhabit many of the Kuiper-belt planets, and have an interesting means of dispersal. Presumably they evolved a bit closer in, long ago, on a planet with temperatures somewhat higher. This may sound like a stretch, but our body temperature is about 30K above our planet's mean temperature.

      Anyway, maybe some day we'll know more about what is possible. Maybe, as Forward imagined, we'll find out when we visit the outer reaches of our solar system. Or maybe not.

      Most of the media attention to possible life is basically silly, and based on little more than speculation. If you want to be entertained by speculation without evidence, you're better off reading science fiction.

      --
      Those who do study history are doomed to stand helplessly by while everyone else repeats it.
    7. Re:Wait... by mrsev · · Score: 4, Insightful

      OK Ill bite:

      >>well, you generally don't find complex life at temperatures where water and most (all?) hydrocarbons freeze,

      Life on earth evolved to use complex hydrocarbons because they "work" well at the temperatures we experiance. Remember that we live at around 300 kelvin. Some things on earth live at 200 kelvin some at close to 450 kelvin. This is quite a wide range. Where hydrocarbons dont work something else will.

      >>do you? i'm sorry you're 'fed up' with this kind of rampant speculation, but given that life anywhere will still have to obey the same physics,

      I think that you underestimate "life" we have plants that eat "light". We live on a planet with an 20% oxygen atmosphere. This was put there by those plants.

      We have bacteria that use sulfur instread of iron. We have creature that change color at will. We have creatures that emmit light. We have creatures that live in the middle of the sahara desert.

      -220 C may be cold for us but what you need for life is a energy differential. Our fish swim in water, birds fly in the air. On another planet they may swim and fly in molten lead or liquid sulfuric gas, somewhere else they may swim in methane.

      On earth some creature survive on caffine solution and hot dogs! There is no reason to assume that alien life should be anything like our own.

      Let me put it this way if you told a 19th century biologist that on earth there were creatures who live at 400 Bar of pressure at +130C in extreme saline conditions they would say it was impossible, that life could not exist under these conditions.

      It is silly to make a prediction of probabilities with a data set of a single sample.(In this case life on earth)We have not even looked properly for life on any of the other planets in our solar system.

    8. Re:Wait... by vsprintf · · Score: 3, Funny

      So it's earth-like how?

      Well, it sounds a lot like North Dakota, so the question becomes, can I get broadband access, and will my company pay for relocation expenses? :)

  2. Oh, Rebecca... by TripMaster+Monkey · · Score: 4, Insightful

    Sorry to carp, but it's stuff like this, especially in 'science' articles, that drives me to distraction.

    From TFA (boldface mine):
    Predicted surface temperatures are minus 220 degrees Celcius (-364F), meaning that its surface is likely to be layer of frozen liquid.
    Umm...wouldn't that be the textbook definition of solid ? In the absence of any information as to the composition of the 'frozen liquid, the term 'frozen liquid' could apply equally well to any terrestrial planet.
    --
    ____

    ~ |rip/\/\aster /\/\onkey

    1. Re:Oh, Rebecca... by Procyon101 · · Score: 4, Interesting

      If you've ever been to a place where liquid water doesn't exist as I have, you very quickly take on a different viewpoint. Water is normally, even on this planet, often a sand or a gravel, undifferenciated from any other mineral at a cursory glance. "Frozen liquid" in reference to water stops having meaning at about -30C because it simply doesn't exist naturally in that state. You start thinking of gasoline and oils as "frozen" or "thawed" instead. Titan gave us a glimpse of an strangely familiar world where water was the predominant mineral and methane was the liquid that rained down and formed oceans.

  3. Just like earth? by nharmon · · Score: 3, Funny

    Cold...inhospitable...sounds like Earth to me.

  4. Earthlike? by tradiuz · · Score: 3, Funny

    So its earthlike in the fact that it is a planet, earth sized, and orbitting a sun? Thats like saying I'm hung like Ron Jeremy, in the fact that we both have a penis and are ugly as sin.

  5. Too bad by NitsujTPU · · Score: 4, Funny

    Unfortunately the planet takes ten years to circle the red dwarf and has a surface temperature estimated at -220 C which means it's just a larger version of Pluto so the chance of finding life on this planet is essentially zero.

    It's especially unfortunate given the ease of a mission requiring us to travel 20,000 light years from Earth, then survive 57.3 Kelvin temperatutes.

  6. Because it's small and rocky. by Anonymous Coward · · Score: 4, Informative

    Unlike all the gas-giant, Jupiter-like planets we've seen so far. It's very difficult to spot tiny, Earth-sized objects from so far away. We may not find this new planet very hospitable but it's still an important discovery.

    1. Re:Because it's small and rocky. by Rei · · Score: 4, Interesting

      I don't see how it would necessarily be incredibly hostile. First off, they don't even have albedo figures for this planet, let alone information on how much greenhouse effect the planet has. Secondly, if this actually is a solid planet that is this massive, it should have ample internal radiological heating, so rough calculations from solar input adjusted by albedo aren't really accurate. Even if the surface is frozen, it should have warm subsurface layers. Ne?

      --
      Musk needs a safer hobby than Twitter. Fire juggling? Cage fighting? Solo hot air balloon trips?
  7. Re:Earthlike? by scheming+daemons · · Score: 5, Informative
    By "earth-like" they meant that it is terrestrial, not a gas giant (a la Jupiter or Saturn).

    Until now.. they hadn't found a planet in another star system that was

    A) terrestrial (solid, with a rocky surface) B) farther than 0.15 AU from its star.

    This planet is 2.5 AU from it's star and it is not a gas giant. That's what makes it "earth-like".. in the way that mercury, venus, mars, and pluto are "earth-like".

    Until now.. no such planet had been observed in another star system.

    All of this is in TFA.

    --
    "I have as much authority as the pope, I just
    don't have as many people who believe it" - George Carlin

  8. Quote from TFA: by Enigma_Man · · Score: 4, Insightful

    Quote:

    "How can we prove there is life on a distant planet when we have problems seeing if there is life on Mars?"

    So, by all means, let's just stop looking then. That's the easy solution. Seriously though, I hate when people think like this. Maybe by looking out into deep space, we'll discover some new method for easily detecting life which we can then apply to Mars. That is unlikely, but still, science is about exploring, not just throwing down the hat at something silly like a problem that we can't quite answer yet.

    Whomever said that hopefully isn't a scientist and/or working on this project.

    -Jesse

    --
    Nothing says "unprofessional job" like wrinkles in your duct tape.
  9. Of course.... by grahamsz · · Score: 4, Funny

    it must be "mostly harmless"

  10. Don't insult us! by 32bitwonder · · Score: 4, Insightful

    This style of reporting is beyond annoying. I'd much rather have this story presented like it is "Using the microlensing technique first predicted by Albert Einstein in 1912, a team of astronomers have discovered a rocky planet about 5 times the mass of the earth some 25,000 light years away. It orbits a red dwarf....." Personally I was more intriqued by Albert Einsteins' involvement than the idiotic claims of the planet being "Earth-like" but.....not.

  11. Official ESO Press Release by Oink · · Score: 3, Informative

    Since I am related to the guy interviewed for the ESO Press Release I feel obliged to link to it.

    http://www.eso.org/outreach/press-rel/pr-2006/pr-0 3-06.html

    I have not read the BBC article. But this is the official PR document. It's nice having relatives in the field. I had this news days ago. :)

    --
    ----------------- Oink. Moo. rarr! -----------------
  12. provincial attitude, dude by Ancient_Hacker · · Score: 3, Insightful
    >the chance of finding life on this planet is essentially zero.

    Well, if you mean life, as in Jessica Alba, you're correct.

    But that's a tad provincial, limited, humdrum, some might say. We know very little about chemistry at 50 degrees Kelvin. Maybe there are some chemical reactions that don't go at all at our room temperature, but run just fine at 50K.

    Might be a tad slow, but who says life has to run at our speed?

  13. Surface Temp of -220 C by aquatone282 · · Score: 5, Funny

    " . . .has a surface temperature estimated at -220 C which means . . . the chance of finding life on this planet is essentially zero."

    Obviously these researchers have never met my ex-wife.

    --
    What?
  14. Little green men on that planet dont agree by Anonymous Coward · · Score: 3, Insightful

    "surface temperature estimated at -220 C ... so the chance of finding life on this planet is essentially zero"

    I am sure the little green men on that planet are saying the same thing about our 32 C planet. "There is no way anything could live on a planet above -100 C."

  15. out of curiosity... by GungaDan · · Score: 4, Funny

    Is there a non-chronological context for the word "ancient?"

    --
    Eloi are stupid, throw morlocks at them!
  16. Re:Basic thermodynamics by Jim_Callahan · · Score: 5, Informative

    Uh, melting point varies with pressure and a couple other factors that depend on your PVT model. You can melt pretty much any material if you set the conditions correctly, regardless of wether the decomposition temperature is below the MP at 1 atm or not. The liquid phase may not be very accessible, but it's always there.
     
    Also, you need a better example, since Sucrose (the molecule people mean when they say 'sugar' without a qualifier) has a MP of 191 degrees centigrade at 1 atm, i.e. it has a viable liquid phase pre-decomposition. Perhaps you're thinking of Glucose or Ribose?
     
    You could make an argument that 'frozen liquid' would refer to an amorphous (non-crystalline/glassy) structured solid only, as these result from a skipping of the phase formation bit of solidification to just lock the structure of the liquid into solid form. However, I think it's more likely that the writers of the article just skipped the materials phase of their education, locking the structure of their brains into a void-filled physics-oriented glass. Or they just, you know, made the intellectual equivalent of a typo. Whichever.

    --
    ...it's really a sad day for America when we require a goddamn ACT OF CONGRESS to make our DVD players work properly. ~
  17. Sensationalist expectations by Bob3141592 · · Score: 4, Insightful

    I can't believe most everyone here is up in arms because the term "earthlike" was used. That basically refers to mass, and is technically correct in it's field. Remember, astronomers refer to anything above helium as "metals." But it leads so many to say "Nothing to see here, there's no giant trees or sea monsters on that planet." How jaded do you have to be to have ridiculous expectations like that?

    That astronomers can detect that planet at all is a phenomenal acheivement. Before this, the only extrasolar planets that could be detected had large masses in close orbits, a rather extreme situation. But here's something quite outside that class. So its parameters aren't inside the "habitable zone." It's the first discovery of its kind. The attitude I'm seeing here is like someone claiming poker is no fun because they haven't been dealt a royal flush on their first hand. It's the process, more than this particular result, that should inspire amazement.

    And it was seen at 20,000 light years away. That really, really far, a galactic distance! That means there are a lot of stars potentially obnservable using this technique. Even if the alignment is relatively rare, with billions of stars to try, perhaps sooner or later one or two will prove themselves to be more interesting to this unreasonably demanding crowd. But then I'm sure the discovery will be discounted if the alien civilization hasn't developed Linux.

    --
    In theory, there's no difference between theory and practice. In practice, there is.
  18. Re:Life Once Upon a Time by bigpat · · Score: 3, Funny

    The more novel thing (to me) would be discovering the ruins of ancient (chronologically speaking) civilization on a planet like that.

    And even more interesting than that would be to discover that the planet was still inhabited, by beautiful amazonian women, and that they had sent a space ship to come get me.

    Short of that, however, I'll take it as very exciting that it might be possible to use this same technique to discover more earth sized planets around other stars in the near future. So that we can use the information to target those solar system for further observation. Then maybe we can start talking about finding another civilization and planets full of sexy alien women and such.

  19. Actually it only takes one year to orbit. by tbcpp · · Score: 3, Insightful

    Anyone should know that each planet takes only one year to orbit it's star. It may take more or less earth years. But that's beside the point.

    --
    Man is the lowest-cost, 150-pound, nonlinear, all-purpose computer system which can be mass-produced by unskilled labor.
  20. Comment removed by account_deleted · · Score: 3, Insightful

    Comment removed based on user account deletion

  21. I helped set up some of their computers by Michael+Woodhams · · Score: 3, Interesting

    Back in about 1995, I was in Auckland finishing up my Princeton PhD, and travelled to the MOA telescope (a pre-existing .6m telescope) when they were setting up their new camera. I installed Linux on about 3 desktop computers in the dome. They had a rack-mounted Sun machine controlling the camera, and there was a pre-existing DOS computer which controlled telescope pointing.

    A few points of interest/weirdnessess
    MOA is a collaboration with Japanese, so all the Linux installs included Japanese language support, including Japanese xterm windows.

    Communication between the Linux boxen and the DOS box was purely by creating/deleting files on a shared drive. E.g. the Linux box would put a file on the drive saying where to point, and then would busy-wait looking at the file until it disappeared, at which point it knew the telescope was now tracking the required location.

    The camera would do 30 second exposures. The Sun box ran a little script to do an exposure, which would send commands to open the shutter, wait, close the shutter, and read the data. The exposure timing was done with a "sleep 30" command! I was *not* happy with that, but didn't convince people to change it.

    Since then, they have built their own new 1.8m telescope, and likely replaced the camera, so the above information is out of date. I haven't had any involvement in the project other than that one trip.

    --
    Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.