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First Rocky Exoplanet Confirmed 155

Posted by Soulskill
from the yo-adrian dept.
Matt_dk writes "The confirmation of the nature of CoRoT-7b as the first rocky planet outside our Solar System marks a significant step forward in the search for Earth-like exoplanets. The detection by CoRoT and follow-up radial velocity measurements with HARPS suggest that this exoplanet has a density similar to that of Mercury, Venus, Mars and Earth, making it only the fifth known terrestrial planet in the Universe. The search for a habitable exoplanet is one of the holy grails in astronomy. One of the first steps towards this goal is the detection of terrestrial planets around solar-type stars. Dedicated programs, using telescopes in space and on ground, have yielded evidence for hundreds of planets outside of our Solar System. The majority of these are giant, gaseous planets, but in recent years small, almost Earth-mass planets have been detected, demonstrating that the discovery of Earth analogues — exoplanets with one Earth mass or one Earth radius orbiting a solar-type star at a distance of about 1 astronomical unit — is within reach."
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First Rocky Exoplanet Confirmed

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  • NTY (Score:5, Funny)

    by T Murphy (1054674) on Wednesday September 16, 2009 @10:31AM (#29439971) Journal
    I appreciate the Rocky movies and all, but there's no way I would live on a whole planet dedicated to them. I'm fine here on Earth, thank you very much.
    • Re:NTY (Score:5, Funny)

      by Monkeedude1212 (1560403) on Wednesday September 16, 2009 @10:38AM (#29440065) Journal

      We recieved some radio transmissions, but all we've decoded so far is You're the best around and Eye of the Tiger.

      • We recieved some radio transmissions, but all we've decoded so far is You're the best around

        Ahh, so they're aware of our existence.

      • Re: (Score:3, Funny)

        by mjwx (966435)

        We recieved some radio transmissions, but all we've decoded so far is You're the best around and Eye of the Tiger.

        This what the actual radio transmission looked like.


    • by Canazza (1428553)

      I was thinking Rocky Horror tbh...
      It's Frank N Furter's home planet *shudder*

    • Re: (Score:3, Funny)

      by SEWilco (27983)
      "Hey, Rocky! Watch me pull a planet out of my hat!"

      What... too late?

    • Such a planet already exists... it's called Philadelphia.

      I happen to be an inhabitant of said planet. My name is Adrian, I welcome you to my world.

      Dead serious, yes, my name is Adrian, and in fact, in my high school there was a also a guy named Rocky, and we were both in marching band and our band once performed "Gonna fly now." Such is the life on my planet, even though I'm a guy.

      *goes back to watching sports and eating cheesesteaks*

  • by Xtravar (725372) on Wednesday September 16, 2009 @10:32AM (#29440001) Homepage Journal

    By the time we actually got to one of these planets, would it still be able to sustain life? Should we be looking for planets that are in their early, less habitable stages?

    • by MBGMorden (803437) on Wednesday September 16, 2009 @10:42AM (#29440113)

      Not really. A lot of these planets that are being found are within the range of a few dozen to a few hundred light years in distance. According to the laws of physics as currently understood, we can't reach light speed, but anything under light speed is fair game. 50% of light speed is perfectly achievable (under the laws of physics - not today's technology), and so most of these could be realistically within 1000 years of travel time. Considering that we had animals walking around on Earth hundreds of millions of years ago, I don't think we'd miss the habitable window of these planets ;).

    • by thisnamestoolong (1584383) on Wednesday September 16, 2009 @11:00AM (#29440365)
      Well, this planet in particular will never be able to support life as it is only about 2.5 million km from its parent star (which is about 23 times closer than Mercury is to our parent star, aka the Sun). Being this close, the planet is likely tidally locked like our moon, meaning that one side of the planet always faces the star. This would make the day side of the planet lava and the night side akin to one of the moons of Saturn (assuming, of course, that there is no atmosphere, which is an exceedingly reasonable assumption to make given the proximity to the star). That means that this planet never was, and never will be, capable of sustaining anything that we know of to be life.

      As planets which could be habitable -- when you speak of the time we actually get to these planets, we are only talking in terms of thousands or tens of thousands of years. These measures of time are beyond insignificant in geological time and would have next to no impact on habitability (barring, of course, sudden events such as asteroid impacts, nearby supernovae, wandering black holes, etc.) -- if it is not yet habitable you can't really count on that changing too much in the next ten thousand (or ten million for that matter) years.
    • We could of course contact them long before we go there...
    • Depends on what you call "life". I think we will send only our neural content there. at first stored as a copy inside robots, who can survive pretty much everywhere where there is light and some minerals. So we can continue a normal life here *and* live on another planet in a million years. And later, we will simply send our minds trough space as digital signals in the form of laser or something like that. We would then truly be those "light lifeforms" of science fiction movies. And we would be able to have

  • Toasty little cinder (Score:5, Interesting)

    by MBGMorden (803437) on Wednesday September 16, 2009 @10:34AM (#29440029)

    Looks like this little guy is only 0.002 AU away from it's parent star. I wouldn't expect to find any life there, but still, this is an amazing discovery. As these methods get fine tuned it's only a matter of time before we start finding planets roughly Earth-like not only in form, but also in relation to the habitable zone around their star. I don't think we'll ever get a probe, much less a person, to any of them within my lifetime, but at least we'll have an interesting list of spots to visit when we do reach that capability :).

    • by CopaceticOpus (965603) on Wednesday September 16, 2009 @11:04AM (#29440427)

      Then again, perhaps their scientists are thinking much the same thing about us:

      "A rocky planet, similar to our own, was discovered in a nearby solar system. However, having only a fifth of our planet's mass, and being located 500 AU from its star, the planet is probably much too cold to support life. Temperatures below 800 degrees are thought to be far too low in energy for the spark of life to begin."

      • You call that cold? (Score:5, Interesting)

        by jeffb (2.718) (1189693) on Wednesday September 16, 2009 @12:55PM (#29442199)

        Meanwhile, as scientists on an outer planet look our way:

        "Rocky planets like the one recently discovered are turning out to be quite common throughout our area of space. Given a dense enough atmosphere, this planet could even support life like ours, although it's hot enough to kill all but the most tolerant extremophiles known. Spectroscopic analysis, though, reveals its deadly nature: much of its surface is covered with molten hydroxic acid, which forms toxic clouds and then falls as corrosive rain. If life-giving ammonia was ever present on the surface, it's long since combined with the abundant free oxygen in the atmosphere. Our chemists are still uncertain what could produce so much free oxygen; fantasists have speculated on forms of life that would metabolize oxygen in the same way that we metabolize hydrogen, but the analogy breaks down quickly as you look more closely at the chemistry involved."

      • by popo (107611)

        And maybe hundreds of millions of years ago they also thought:

        "It's not worth going to that barren rock because it would take 10,000 years to get there, but let's fire off a probe filled with genetic material at that rock and see if anything evolves -- y'know for shits and giggles"

      • I can accept that alien scientists would use english, but I don't think they'd say "similar to our own" if they were going to immediately say how different the two planets were. Good communication is good communication.~

      • by T.E.D. (34228)
        Heh. The "500 AU" was a nice touch. :-)
    • by oodaloop (1229816)
      Most of the planets found so far are very close and/or very heavy precisely because they are easier to find. Closer/faster/bigger planets produce more wiggle in the orbit of their parent star than smaller/slower/lighter ones.
    • We've already found some tantalizing prospects. Perhaps the best is Gliese 581d, which is a super-Earth (anywhere from 8-13 Me) that's within its star's habitable zone. We've even started broadcasting to it, just in case.

      COROT 7b is interesting because it's only 5 Me, and because we were able to calculate its density and prove that it's a rocky planet. There will be other prospects. We're getting pretty good at this planet hunting game.

  • Is it class M?

    It might have Roddenberries.
  • Not really the first (Score:3, Informative)

    by EdZ (755139) on Wednesday September 16, 2009 @10:42AM (#29440121)
    Smallest maybe, and the first to have a confirmed radius value, but hardly the first rocky exoplanet discovered. PSR 1257+12 [] wins by about 18 years.
  • by gzipped_tar (1151931) on Wednesday September 16, 2009 @10:43AM (#29440137) Journal

    Here's a scientific paper describing how the period/mass/size/etc of the planet was deduced from observation data: []

    According to the paper, this planet's orbital semimajor axis (or in plain English, the "average" distance from the planet to the sun) is about 0.0172 astronomical units. Since its sun's temperature is roughly at the level of our Sun (also in the paper), it means the planet is probably a hell much hotter than the Earth...

  • by doti (966971)

    I'm packing my bags

  • by soboroff (91667) on Wednesday September 16, 2009 @10:56AM (#29440319)

    .... watch me pull a planet out of my hat!

  • by Fallingcow (213461) on Wednesday September 16, 2009 @11:06AM (#29440453) Homepage

    Maybe jump to the left?

    Then a step to the right, perhaps?

  • by SnarfQuest (469614) on Wednesday September 16, 2009 @12:03PM (#29441311)

    In the grand tradition of selling things you don't own, like the names of stars and acres on the moon, I hereby offer to sell 40 acre lots on this planet for a mere $10,000 each. That's cheaper than a lot this size would cost in any large city here on earth. Imagine what you could do with your lot. Since there isn't any law enforcement there yet, you could grow illegal crops, build a manufacturing plant without any polution controls, or just use it to test your nuclear bombs. This is a limited time offering, and quantities are limited, so don't delay. And if you order today, we'll include the plans for a trebuchet so you can fling dead animals onto your neighbors property.But wait, order during this program, and we'll include a set of ginzu knives (shipping, handling, and other fees are an additional charge) which can cut through the toughest tomato without the need for a hammer, but you'll want to use one anyway just for the splattering fun.

  • Soon to be followed by Rocky 2, Rocky 3 and Rocky 4. All of which will suck.
  • This planet is too big, too close to its Sun, and orbiting too fast to be habitable in any way we are accustomed too. But this doesn't mean its discovery is not news: Astronomers are finding more evidence that planets are common. Progress is being made towards discovering planets more like our own than the gas giants which were first discovered.

    What is needed is more telescopes of good sensitivity. Each main sequence star not wholly unlike our own needs to be carefully monitored over time, in order to detec

  • by jc42 (318812) on Wednesday September 16, 2009 @02:58PM (#29444221) Homepage Journal

    The summary (and TFA too ;-) reminded me of the recent debate over the definition of "planet".

    One obvious problem is with the claim that we only knew of four "rocky planets" before this one. Since Mercury and Mars are included, it's likely that the definition they're using would also classify at least Titan and Triton as "rocky planets", giving us six.

    But, (I can hear people saying), Titan and Triton aren't planets because they don't orbit the sun. Well, neither does this new planet; it orbits another star. Some people have seriously defined "planet" to mean objects that orbit our sun, and of course that definition immediately says that there can't be any more planets in the rest of the universe. If you accept this new object as a "rocky planet", what's your definition? You'll have to word it very carefully so that it includes things orbiting a distant star, but not those that are in orbits around local gas giants.

    And if you find a good wording for that, you face another likely future problem: How small an object is allowed as the primary? Suppose a new rocky-planet-like object is found in orbit around a nearby "brown dwarf". The primary isn't a proper star, so is the object merely a moon and not a planet? It's also likely that we'll soon find Jupiter-class objects in free space, not orbiting a star; if one has a Mercury- or Mars-like object in orbit, would it be classified as a rocky planet or a moon? If it's a planet, then why isn't Ganymede also a planet?

    I'd predict that in the not-too-distant future, as smaller things can be detected remotely, astronomers might decide to abandon such definitions that depend on the type of primary, and rewrite definitions so that they only use properties of the object itself. Either that, or they'll deprecate "planet" as a lay term that's not useful for scientific purposes. Dunno what they'd replace it with, though.

    Meanwhile, the Sophists amongst us may be in for a lot of fun in the near future. Those of us who sat at the sidelines chuckling over the angst caused by the demoting of Pluto are probably looking forward to a lot more astronomical geek humor in the next few years.

    • by emurphy42 (631808)

      Some people have seriously defined "planet" to mean objects that orbit our sun, and of course that definition immediately says that there can't be any more planets in the rest of the universe. If you accept this new object as a "rocky planet", what's your definition? You'll have to word it very carefully so that it includes things orbiting a distant star, but not those that are in orbits around local gas giants.

      And if you find a good wording for that, you face another likely future problem: How small an ob

    • by nofx_3 (40519)

      Pluto got that shaft again in this article. Not even a nod as the former 5 rocky planet.

    • by 4D6963 (933028)

      A rocky planet orbits the sun. A rocky exoplanet orbits other suns. But who cares anyway? It's just us pigeonholing the objects we see in the sky.

  • I know it's cool and all, but a giant planet in the habitable zone is more important than a rock planet hovering close to its star's burning atmosphere. Imagine a Saturn + Titan in the habitable zone. We'd only see the Saturn from here, but we can assume that such a planet might have large moons, moons capable of sustaining a dense atmosphere (which I know isn't the most common thing, but still).

    Let's imagine a Titan around whichever giant exoplanet we know that's in the habitable zone, and that it has th

  • It would be nice if news submissions to *science* contained hard data URLs, rather than simply paraphrasing other press releases. I would like for example to know precisely *what* us being measured and how it is being measured (brightness vs. radial velocity, spectroscopic planet "light" frequency shifts, etc.). If you only know the orbital period and a radial velocity shift then it would be complete "fiction" (or "certitude" based on dead universe physics). With only a couple of parameters

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