Waterworld DIscovered

Call Kevin Costner:

But extraordinary may be too understated a descriptor for the discovery reported on Wednesday in the journal Nature: an international team led by Harvard astronomer David Charbonneau has spotted a "super-Earth," a planet 2.7 times bigger than Earth, circling a dim red star called GJ 1214, just 40 light-years away in the constellation Ophiuchus. "It's spectacular," says Geoffrey Marcy of the University of California, Berkeley, who is the world's most prolific planet hunter and is credited with discovering 70 of the first 100 exoplanets. "It's a top-of-the-top discovery in the quest for Earth-size planets."

While the new planet, dubbed GJ 1214b, is too big to be considered Earthlike, it comes pretty close. But GJ 1214b's relatively compact size — smaller than the vast majority of planets identified so far — is only one reason for astronomers' enthusiasm. Another is GJ 1214b's likelihood of bearing the stuff of life: water.

If you're looking for a world where life might thrive, a planet must be at the right temperature for water to exist in liquid form. So it needs to orbit its star in the so-called habitable zone, a "Goldilocks" location that allows a planet to be neither too hot nor too cold. In that respect, GJ 1214b is again a near miss. Its surface temperature hovers at a sweltering 190°C (374°F), which is well above the boiling point of water, at least in Earth's atmospheric pressure. Fortunately, GJ 1214b's atmosphere makes the pressure a lot higher than on Earth — "crushing," as Charbonneau describes it — and increases the odds of liquid water.