New Super-Earth: Hot, Watery, and Nearby

By Andrew Moseman | December 17, 2009 11:18 am

Waterworld220And the exoplanet count marches on. A few days ago astronomers announced they had found a handful of new planets around sun-like stars, some only 29 light years away. Now, in a study published today in Nature, a team led by David Charbonneau unveils a new super-Earth that’s hot, watery, and only 2.68 times the size of our own world.

The planet currently bares the name GJ 1214b, and while Charbonneau says it’s probably not habitable (because of the 400-degree Fahrenheit surface temperature), it’s not too far off the mark. Geoffrey W. Marcy, a planet hunter from the University of California, Berkeley, wrote in an accompanying article in Nature that the new work provided “the most watertight evidence so far for a planet that is something like our own Earth, outside our solar system” [The New York Times].

Despite the heat, the astronomers say, their new planet most likely holds a lot of water. By determining the new world’s mass and size as it passed in front of its star, the researchers could calculate its density: one-third that of Earth. Because water has a much lower density than rock, astronomers figured that the “most plausible scenario is a planet made mostly of water, with a significant atmosphere,” says Charbonneau. So despite its high temperature, GJ 1214b’s high atmospheric pressure and relatively low density mean liquid water could exist there after all [TIME].

Finding GJ 1214b didn’t take a giant telescope or a space observatory like NASA’s Kepler mission. The team used an array of smaller telescopes on an Arizona mountaintop, and project called MEarth. Relatively dim, relatively close stars were favored because the planet’s dimming effect would be more noticeable than it would be with brighter, bigger, farther-out stars [MSNBC]. One of Charbonneau’s graduate students noticed the blip as the planet passed in front of its star, and it didn’t take long to confirm the find: GJ 1214b orbits its M-dwarf star once every 38 hours.

Related Content:
80beats: Meet the New Neighbors: Earth-Like Worlds Orbiting Nearby Stars
80beats: A Profusion of Planets: Astronomers Spot 32 New Worlds Around Distant Stars
DISCOVER: How Long Until We Find a Second Earth?
DISCOVER: The Inspiring Boom in Super-Earths
DISCOVER: Space Scientist: Geoff Marcy and Paul Butler

Image: David A. Aguilar/CfA

  • YouRang

    The planet talks!? It might bear the name GJ… but it certain cannot bare anything.

  • rabidmob

    Any calculations as to how fast the planet is moving?

  • Arik Rice

    Just because it’s hot doesn’t mean its uninhabitable. On Earth, there are undersea vents which get hotter that are just teeming with life. If life exists there, it would probably be well adapted to swim in 400-degree oceans (and actually it may be cooler than than, depending on the planet’s albedo).

  • StevoR

    Awesome news! 8)

    You beat the Bad Astronomer to it here! 😉

    Its already on Wikipedia too see :

    Complete with a comparison with Earth & Neptune & full spectral class of the host star as an M4.5 V red dwarf.

    It may well be more like a Hot Neptune than a SuperEarth but this is still a marvellous discovery and hopefully the first of many. :-)

    It could use a proper name though – might I suggest ‘Oceanus’ or ‘Poseidon’ after the greek mythological gods? Or at least the name /nickname ‘Calypso’ after the nymph who imprisoned legendary sailor & King of Ithaca Odysseus and the “pirates of the caribbean” sea goddess? An association with hot imprisoned waters seems apt here somehow! 😉

  • Bill J

    How long will it be before Al Gore blames us for the conditions on GJ1214 b??

  • Dave in Calif

    Bill not just blame us, but blame Bush.

  • http://..... anna

    i think we should call it one of these names at least- Alina,planet 51,therdropia,galypso or even, sauresdor also do you think we can actually can live there it would cost to much to send people over there and is there any living thing already on that planet like humans .

  • pug puppies for sale

    You made some great stuff there. I did a searching on the content and found the majority of people may agree with your blog.


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