Planet Population Explodes
In the same year the U.S. conducted its decennial census, astronomers continued their ongoing nose count of known planets outside our solar system — and they found a lot of new celestial citizens. There's HIP 13044b, a world circling a distant star that was once not even part of the Milky Way, but was instead snagged by it gravitationally. There are up to seven new planets orbiting a star called HD 10180, about 127 light years from Earth. Most exciting was the discovery of Gliese 581g, the first extrasolar planet discovered that orbits its sun in the so-called Goldilocks zone, a distance at which conditions are neither too cold nor too hot for life. Alas, this Goldilocks may indeed be a fairy tale, as follow-up studies have now cast doubt on whether the planet exists at all. But few scientists doubt that more worlds like are out there — or that they'll be discovered soon.