NASA's planet-hunting spacecraft, Kepler, has made radical new discoveries about a hellish planet a thousand light years away -- proof, scientists say, that the craft will be able to carry out its mission of finding other Earths in our galaxy, provided they exist.
NASA scientists released Kepler's analysis Thursday of an already known "hot Jupiter" planet called HAT-P-7b in the constellation Cygnus. The spacecraft mapped the planet's orbit and gave new details about its hazy, ozone-like atmosphere, where temperatures climb as high as 5,000 degrees Fahrenheit.
The analysis proves that Kepler's onboard telescope and light-detecting instruments are at least 100 times more precise than the ground-based detectors that originally found HAT-P-7b, the scientists said at a briefing at NASA headquarters in Washington. That should be good enough to spot any pint-sized planets -- about the size of Earth -- in a star's so-called habitable zone, where temperatures are warm enough for water to be liquid but not so hot as to torch the planet's surface.
"Kepler has the ability to detect Earth-sized planets," Alan Boss, an astrophysicist with the Carnegie Institution of Washington, said at the briefing. "The question that remains is: How many Earths are there?"
Kepler, which was launched in March, is the first spacecraft with a mission to find potentially habitable worlds. Over the next few years, as it circles the sun in an Earth-trailing orbit, it will scan 100,000 stars in the constellations of Cygnus and Lyra, looking for planets.
Of the previously discovered 350 or so extrasolar planets -- those that lie outside our solar system -- none is a candidate for the "Goldilocks" planet, where things are just right for life to gain a foothold. Teams in Europe and the United States have found several super-Earths, planets that are slightly larger than our home planet. But all are either too close to their star and thus baking hells like Venus, or too far away and therefore ice-cube worlds like Pluto.
Since the launch of Kepler, controllers have spent most of their time tuning its sophisticated instruments, which are designed to detect the tiniest variations in light from a star thousands of light-years away that might indicate a planet orbiting it. Only in the last few weeks has the science team begun putting Kepler through its paces, gathering data.
