The best looks that we've been able to get at exoplanets are when they pass in front of or behind their parent stars. When that happens, sometimes, if we're lucky, we can get a brief hint atmosphere. For the first time, NASA's Spitzer Space Telescope has managed to observe a "super-Earth" directly, watching it glow in the infrared.
In the visible spectrum, the light from a star vastly outshines the light from any planets around that star. But in the infrared, planets radiating heat are significantly brighter. The planet in question is about 40 light years away and called 55 Cancri e, and it's a super-Earth, about twice as big (and eight times as massive) as Earth is. As NASA puts it, 55 Cancri e is a "toasty world," orbiting close enough to its parent star that its year is just 18 hours long.
Spitzer isn't capable of resolving 55 Cancri e on its own, but it can measure the decrease in light when the planet circles behind its star. From that change, it's possible to determine what light is being emitted by the planet itself. Planetary scientists had hypothesized that the planet was a sort of water world, a rocky core surrounded by a layer of water and a blanket of supercritical steam. Spitzer's latest observations seem to confirm this, since 55 Cancri e appears to be tidally locked with a surface temperature somewhere in the neighborhood of 3,000 degrees Fahrenheit.
When the James Webb Space Telescope launches in 2018, NASA hopes to use this same infrared technique to check out potentially habitable exoplanets, looking for signs of life. 2018, folks: that could be the year we finally spot something that proves we're not alone out here.
Via NASA
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