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First Exoplanet Atmospheres Analyzed

Posted by samzenpus on Wed Feb 21, 2007 06:57 PM
from the the-smell-of-exoplanets-in-the-morning dept.
Space Science
deblau writes "NASA's Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of individual molecules in their atmospheres. The landmark achievement is a significant step toward being able to detect possible life on rocky exoplanets and comes years before astronomers had anticipated."
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[+] 28 New Planets Found Outside Solar System 258 comments
elkcsr writes "The San Jose Mercury news reports on the phenomenal discovery of 28 new extra-solar planets out there in our galaxy. All of them are outside of the band scientists consider necessary for supporting life as we know it, but the solar systems analyzed should still be quite familiar to those of us in this neck of the woods. System layouts feature small rocky planets towards the star and gas giants further out. The biggest difference seen is a preference for elliptical orbits, instead of generally circular orbit we enjoy. ' For example, the team also described new details about one specific exoplanet, discovered two years ago. This planet, which circles the star Gliese 436, is thought to be half rock, half water. Its rocky core is surrounded by an amount of water compressed into a solid form at high pressures and low temperatures. It makes a short, 2.6-day orbit around Gliese 436. Based on its radius and density, scientists calculate that it has the mass of 22 Earths, making it slightly larger than Neptune. "The profound conclusion is, here we've found yet another type of planet that is already represented in our solar system," Marcy said.'"
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  • EPA (Score:5, Funny)

    by Tablizer (95088) on Wednesday February 21 2007, @07:02PM (#18103142) Homepage Journal
    Shit! They are all polluted also.
  • Would buy (one) of our dusty new exoplanetary overlords a drink. (Before they obliterate us for our water.)

    The lack of water on these planets is interesting. While the articles indicate that the water may just be masked by higher atmospheric layers, one would think that there would be some water to be found.

    • Re:I for one (Score:4, Funny)

      by Original Replica (908688) on Wednesday February 21 2007, @07:21PM (#18103332) Journal
      Our exoplanetary overlords don't want our water. What would a sentient cloud of silicon crystals want with H2O? They are just trying to figure out if the silicon chips of our planet are willing to sell a few of their pet waterbags. (that's us)

  • they can read the fine print (Score:4, Funny)

    by User 956 (568564) on Wednesday February 21 2007, @07:08PM (#18103214) Homepage
    NASA's Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of individual molecules in their atmospheres.

    Jesus. If they can see that far out, imagine what they can see when they look straight down.

    • Re:they can read the fine print (Score:4, Funny)

      by flyingsquid (813711) on Wednesday February 21 2007, @07:31PM (#18103442)
      Jesus. If they can see that far out, imagine what they can see when they look straight down.


      NASA says that if you don't stop doing you-know-what, you're going to go blind.

      • NASA says that if you don't stop doing you-know-what, you're going to go blind.


              So, following your logic - the NASA geeks have never done "you know what", since they are able to see so far ? Makes sense :P
      • > > Jesus. If they can see that far out, imagine what they can see when they look straight down.
        > NASA says that if you don't stop doing you-know-what, you're going to go blind.

        No, that's NSA, not NASA.

        (Keyhole cat is watching you masturbate, but he works for NRO, not the other two agencies ;)

    • Re:they can read the fine print (Score:5, Informative)

      by iamlucky13 (795185) on Wednesday February 21 2007, @08:43PM (#18103976)
      I figured somebody better follow the joke up with some clarification. The optics on Spitzer, like Hubble, aren't focused that close. Plus it's infrared. Skin complexion would look like crap.

      Also, they aren't directly seeing the planet. I don't know if Spitzer's cameras could theoretically resolve it, but I do know it can't pick it out of the glare from its star. The method is to use a spectrograph and note really carefully the spectra of light received from the observation. When the planet, which is emitting light at different wavelengths depending on the molecules present, goes behind the star, this spectra changes ever so slightly. From this you know which portions of the spectra are from the star and which are from the planet, and you can deduce the molecules based on characteristic spectral lines.

      This is very much like colors on an LCD monitor. Let's say you have a switch that will let you turn off one pixel of a triad (the triad being the red, green, and blue pixels that make up a visible pixel), but you don't know what color it is. If you see a yellow pixel, you know there is actually a red pixel and green pixel turned on right next to each other, even though your eye can't resolve them. You flip the switch and the visible pixel turns red, so you know the pixel you control is green. The colors of the pixels are analogous to the molecules on the planet versus the star. The pixel you can control is like the planet, but instead of a switch it goes behind the star.

      Since the article apparently likes big numbers over useful units, the 370 and 904 trillion mile figures for the distances to the two observed targets are equal to 63 and 153 light years respectively.
      • The optics on Spitzer, like Hubble, aren't focused that close.

        Isn't there a point where the depth-of-field and resolving power sort of meet?
        That is, something at 10m and something at 10km are both pretty much at the same focus for my 38mm camera lens if I have a reasonable aperture. Setting it down to f/16, I can get pretty sharp shots from about 1m to infinity.

        For Hubble/Spitzer however, the difference between something 20m away and 100km away is (probably!) quite obvious, but the difference between 100km

        • Re: (Score:3, Informative)

          by ColaMan (37550)
          Never mind - from a bit of online searching of some old archives [textfiles.com], it would appear that Hubble's limit of focus is about 10000km -> infinity without adjustment. The range of adjustment needed to make in-focus observations of the ground is pretty small however (12mm or so), so it's quite possible that it could be done.

          But why you would do that when there are no doubt perfectly good spysats out there with better resolution, I don't know.

    • Re: (Score:2, Interesting)

      by Anonymous Coward
      I have it direct from a group of Hubble engineers that if the day side of earth ever gets in view of HST, it'll burn the camera out completely. The lenscap/door thing on the business end always opens toward earth for this reason.

    • Jesus. If they can see that far out, imagine what they can see when they look straight down.
      AAAAAAAArh! Mental image of the Goatse.cx-guy!

  • So Our First Sign of Extraterrestrial Civilization (Score:4, Funny)

    by Phrogman (80473) on Wednesday February 21 2007, @07:10PM (#18103240) Homepage
    ... will be when we discover a planet with a huge hole in its ozone layer? :P
    • I think we'd be more amazed to discover a planet with an ozone layer, period. Add a spun-iron-core magnetic field to it and we'd be ecstatic.

      • I think we'd be more amazed to discover a planet with an ozone layer, period.

        This is more true than probably most slashdotters realize. Ozone is the only chemical indicator of life that we can reliably detect across long distances.

        Ozone, unlike oxygen itself, has a strong absorption spectrum in the infrared wavelengths. A space-based infrared telescope (like Spitzer, but better) is exactly the right tool for detecting the presence of ozone. (A ground based telescope will not do, since infrared is absorbed by the atmosphere.) Finding ozone on a planet is just like finding oxygen -- the two compounds are so closely related that you can't have one without the other. And oxygen is a very volatile compound that reacts with almost anything else if you leave it alone. The only way for a planet to have free floating oxygen is if something on the planet is producing it.

        As far as we know, the only way to sustain an oxygen atmosphere on a planetary scale is with life. So, yes, finding ozone on a distant planet would be a very exciting discovery indeed.

        • Re: (Score:3, Informative)

          by Rei (128717)
          Well, not necessarily. Oxygen (and thus ozone) can be produced in macroscopic scales abiotically. Some classes of water worlds should do this, for example. They don't have a surface that wants to oxidize, and if they're massive enough, they'll hold onto an oxygen atmosphere produced through photochemical means. Some moons in our solar system, like Europa, have tenuous oxygen atmospheres.

          Likewise, other chemicals that we're not used to would probably still scream out "life" to us. What if you saw an atm

  • Check their accuracy a year from now (Score:3, Interesting)

    by PDMongo (225918) on Wednesday February 21 2007, @07:11PM (#18103242) Journal
    What will be really interesting will be to see how accurate their atmospheric analysis will be a year from now. In the article they mentioned finding tiny particles of "silicates in the atmosphere". Sounds a like a lot of speculation as to what the actual data could represent.
    • What will be really interesting will be to see how accurate their atmospheric analysis will be a year from now.

            Even more interesting to see how accurate it is 5000 years from now, when we send someone (or a probe) there ;)
    • What I find interesting is that they found these results ahead of what was expected. /.er always whine that many stories presented here are about things that are "3 to 5 years into the future" (and they seem to be "Microsoft years", you know, like when you are installing something on Win* and it keeps telling you '5 minutes left to finish' for about 30 minutes =P ) so it's nice to hear this is the other way around for a change!

  • Alien Infiltration? (Score:5, Funny)

    by Anonymous Coward on Wednesday February 21 2007, @07:14PM (#18103274)

    "The theorists' heads were spinning when they saw the data," said Dr. Jeremy Richardson of NASA's Goddard Space Flight Center, Greenbelt, Md.
    Better have some xenobiologists check those guys out. Or a priest.

  • Subtraction works (Score:5, Interesting)

    by Tablizer (95088) on Wednesday February 21 2007, @07:17PM (#18103290) Homepage Journal
    I think it is amazing how they can get the spectrum of the planet by substracting the spectrums of both using a formula like:

        planet = (star + planet) - star

    In other words, take the spectrum of both and compare it to the spectrum of the star when the planet is behind the star.

    It seems to me the star's spectra would be so strong as to wash out anything from the planet. However, maybe the specific chemical signatures they are looking for are weak in the star. For example, stars are probably too hot for a water line. Water would probably be converted into fundimental elements by the star.
                 

    • Re: (Score:3, Informative)

      by 1fitz2many (409956)
      These data were taken in the mid-infrared, where the contrast between the star and the planet is not as great --- only about 200--300:1, instead of 10^6--10^10 to 1 in the optical/near-IR.
    • It sounds like they weren't at all sure they could do it. Double coolness that the results were surprising.

  • Not earth like (Score:5, Informative)

    by rossdee (243626) * on Wednesday February 21 2007, @07:31PM (#18103444)
    All the extra solar planets that have been found so far are large gas giant type planets.

    Our telescopes aren't good enough (yet) to detect small earth size rocky planets.

    While spectographic analysis of these planets atmosphere is interesting, it does not give us information about the possiblity of life (as we know it, Jim) since these aren't the places we would find life in this solar system either. Maybe these other planetary systems do include rocky planets, or moons (like titan and europa ) that could be candidates for some form of life, but we wouldn't find that out by looking at the atmospheres of JUpiter and Saturn

    • Re:Not earth like (Score:5, Interesting)

      by 1fitz2many (409956) on Wednesday February 21 2007, @08:52PM (#18104026) Homepage
      There have been some recent discoveries of some "super-Earth" planets, e.g. GJ 876d [harvard.edu] and a planet found through gravitational microlensing [harvard.edu], that have masses several times that of Earth. In the core-accretion scenario for planet formation, it's hard to stop runaway gas accretion once it gets going, suggesting that such low-mass planets are rocky and not gaseous. Perhaps they're the remnant cores of former gas giants that have lost their gaseous envelopes via some process that occurred after formation.

    • Re: (Score:3, Interesting)

      by David_Shultz (750615)
      it does not give us information about the possiblity of life (as we know it, Jim) since these aren't the places we would find life in this solar system either.

      Even if we are only looking at gas giants, at the very, very least, wouldn't it help us better understand the chemical makeup of neighbouring solar systems, and aid in the development of more accurate models of solar system formation (which will in turn help us better understand the probability of life elsewhere a la Drake equation)? Isn't it also qu
      • Thanks for mentioning the Drake equation. Slowly but surely we are chipping away at the variables in that famous equation. Michael Crichton gave a famous lecture harshly mocking the Drake equation (emphasis is mine):

        N=N*fp ne fl fi fc fL

        Where N is the number of stars in the Milky Way galaxy; fp is the fraction with planets; ne is the number of planets per star capable of supporting life; fl is the fraction of planets where life evolves; fi is the fraction where intelligent life evolves; and fc is the

    • Yup, and a mere ten years ago people were carefully explaining why spectroscopy of exoplanets was nigh-on impossible and many decades away at best. At the rate things are happening it will be fascinating to see what we know a decade from now.
  • Until they can read a Starbucks sign there won't be proof of extrasolar geeks. I'd say reading a Red Bull can but that's probably asking too much.

  • Nitpick (Score:3, Informative)

    by E++99 (880734) on Wednesday February 21 2007, @08:14PM (#18103784) Homepage
    I'm sorry, but they are not detecting the signatures of INDIVIDUAL MOLECULES. Try "individual compounds".
  • I really think that the skills needed to analyze a distant planets atmosphere are important. But it doesn't matter what they discover, the information that the telescopes gather is billions of years old and is likely completely to be worthless for the purposes of planning exploration. It is still cool though.

    • Re: (Score:3, Informative)

      by khallow (566160)
      The more distant system is 150 lightyears away. Since that is also how much time it takes to light reach here, the data is "only" 150 years out of date.
    • These data are far less than a million years old. Except in case we got a very rare alignment of gravitational lense phenomena would we be able to observe any exoplanets outside our own galaxy. Hence, all these planets are within our own galaxy and so the data should reflect the current state, on a geological timescale.

  • Maybe they're using the Smelloscope (Score:4, Funny)

    by Dachannien (617929) on Wednesday February 21 2007, @08:32PM (#18103912)
    Professor Farnsworth: Now, we all know telescopes allow us to see distant objects. But what if we want to smell distant objects? Well, now we can! Thanks to my new invention: the Smelloscope. The odor travels past this coffee stain here, around the olive pit, and into this cigar burn. And this appears to be a doodle of myself as a cowboy. But the Smelloscope is brilliant, I tell you! Think of the astronomical odors you'll smell, thanks to me.

  • Not the First, Folks (Score:3, Informative)

    by CheshireCatCO (185193) on Wednesday February 21 2007, @09:27PM (#18104282) Homepage
    This is great research and all, but I would think that the people at Spitzer would be a lot more cognizant and courteous to their colleagues and not inflate their claims of priority. A team already analyzed the atmosphere of a transiting exoplanet using STIS on Hubble. It's a different situation (most exoplanets don't transit, after all), but they HST team did this around five YEARS ago. I remember hearing talks about it at the time, it was a big deal. Surely the Spitzer team should have known about this?
  • From the article:

    HD 189733b is 370 trillion miles away in the constellation Vulpecula, and HD 209458b is 904 trillion miles away in the constellation Pegasus.

    Dammit, man, use metric! How many football fields is that?

    • Dammit, man, use metric! How many football fields is that?

      Which kind of football: Canadian, American, Australian, or International? :-D

    • Well according to my TI-86 calc, (if trillion = 10^12) 370 trillion mi is 62.94 LY. 904 is 153.78 LY

      According to Celestia, HD 189733 is 62.795 Ly away from Sol.
      " " HD 209458 is 153.56 LY away from Sol.

      Whats neat is the most recent version of Celestia has planet "b" on the further away one. Kinda cool to see the absolute brightness when grazing its surface. It'd look really hot.
  • It is beautiful to read about such a scientific achievement, the technology involved and the vision of the scientists that implement it. From the results obtained an article is written that appeals to "the man in the street" and light-years are converted into xx trillion miles. After that you get to the comment section and this is just depressing. We need to return to proper science articles even in the poplar press and general web sites and if some people are not able to follow they have a choice: get inf

  • Informative summary (Score:3, Informative)

    by Yvanhoe (564877) on Thursday February 22 2007, @04:28AM (#18106628) Journal
    Here are the informations missing from TFS :
    Two extrasolar gas giant upper atmospheres were observed by the Spitzer infrared sprectrometer. It revealed mainly silicate dust and no water. That bewildered scientists who take for granted that such planets contain a high quantity of water. They extrapolate that it must be present under the dust layer.
    • God I hope not, last thing we need is another Hollywood. Although the idea of moving them off planet certainly is appealing.

      • Re:However, due to lack of federal support (Score:5, Interesting)

        by MightyMartian (840721) on Wednesday February 21 2007, @08:10PM (#18103738) Journal
        That's not NASA's fault. That's the fault of greedy, whorish, self-serving Congressmen who, in place of a sense of vision and wonder, hold their proverbial genitals in their hands making idiotic demands upon the agency before they'll vote on funding. The ISS that was originally proposed would have been quite something. A space shuttle that actually followed the initial requirements would have been incredible. But by the time it was all filtered through the worthless filth that inhabits Washington, we were left with a pack of crap.

      • blow money in frivolous ways on things like ISS and the space shuttle missions, instead of things that are more cost effective?


        NASA could teach us everything there is to know about space but what exactally is the point if we never figure out how to live and work there?

    • If we found an earthlike planet that's earthlike enough (or rather, a combination of substances that you wouldn't expect, like free oxygen and methane), that would certainly indicate some interesting chemistry going on. Anything out of equilibrium is interesting. Of course, we can imagine some kind of mineral that will actually do that when exposed to light from the star without going over the hassle of "life", but if we can guesstimate the age and the current rate, there can be some chances to define quite
    • It is scientific research. It does not have to have a praktical use. That's what engineers are for. If you can't think of anything to do with it, fine, there's more than likely someone who is going to come up with an idea of what to do with this tech and make a fortune on it.

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