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Scientists Discover Exoplanet Less Than Twice the Mass of Earth

Posted by Soulskill on from the it's-so-small dept.

Snowblindeye writes with this excerpt from the European Southern Observatory: "Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, 'e,' in the famous system Gliese 581, is only about twice the mass of Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist. Planet Gliese 581 e orbits its host star — located only 20.5 light-years away in the constellation Libra ('the Scales') — in just 3.15 days. 'With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet,' says co-author Xavier Bonfils from Grenoble Observatory. Being so close to its host star, the planet is not in the habitable zone. But another planet in this system appears to be. ... The planet furthest out, Gliese 581 d, orbits its host star in 66.8 days. 'Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star,' says team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. '"d" could even be covered by a large and deep ocean — it is the first serious "water world" candidate,' continued Udry."

4 of 201 comments (clear)

  1. Re:Wanna see more: Celestia by SalaSSin · · Score: 0, Redundant

    Oh, and btw: our sun is about 20 light years away from Gliese 581d. (Also found in Celestia)

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    Any sufficiently advanced incompetence is indistinguishable from malice - Grey's Law
  2. Re:Planets and moons by lazyforker · · Score: 0, Redundant

    Gliese 581 d is probably too massive to be made only of rocky material...

    Even if it isn't habitable, it might still be large enough to have a habitable moon perhaps?

    That's no moon.

  3. Re:but what about Earth 2... by nautsch · · Score: 0, Redundant

    Whoa, that was wrong.

    1. There is not an infinite amount of space
    2. since when is infinity - x = something finite?

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    If you find a typo, you may keep it.
  4. Re:Astronomy by dragonbutt · · Score: 0, Redundant

    directly image a nearby terrestrial sized planet.

    You must be using VERY large values of nearby

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    it was like that when I got here.. I wasen't here when that happened... second shift musta done that....