The discovery of a new planet has always been exciting, but the bloom is starting to come off the rose now that we’ve done it more than 400 times. A University of California–Santa Cruz team announced the discovery of six new planets orbiting two stars earlier this week, but they weren’t even the toast of the exoplanetology world, much less international newsmakers. Those honors went to a team led by Harvard’s David Charbonneau.
Quality trumps quantity when it comes to such discoveries, and Charbonneau’s planet has a number of newsworthy traits. At more than six times our own planet’s mass, it’s a “super-Earth,” but this new world’s relatively low density means it’s likely made mostly of water. Though it orbits uncomfortably close to its star, the planet’s water may be kept liquid at 200° C by a dense, highly pressurized atmosphere. Not exactly a tropical paradise (though Dennis Overbye’s New York Times headline describes it as “sultry”), but easily the most Earthlike planet we’ve been able to characterize thus far.
Orbiting the red dwarf star GJ 1214 in the Ophiuchus constellation, the planet is also quite nearby by astronomical standards. At a distance of 42 light-years, it would still take several thousand lifetimes for us to get anything there, but its close proximity makes it an excellent target for ranged study by the James Webb Space Telescope scheduled to launch in 2014. In the meantime, the aging Hubble and Spitzer space telescopes may be used to study this bizarre waterworld.