If Another Earth Is Out There, Kepler Will Find it

If there's truly no place like home, then NASA's new Kepler mission will help scientists prove it. The space telescope, set to launch March 5, will scan the skies for planets with the approximate size and temperature range of Earth. Matches could be candidates for extraterrestrial life; if Kepler finds nothing, it may mean we're all alone, writes Wired.

The telescope will be able to detect smaller planets than its predecessors did by measuring the changes in light from distant stars as planets pass in front of them. The qualifications for an Earth-like planet include similar size, distance from its sun, and length of orbit; if such bodies are common, Kepler should find about 30 to 50, but it can't tell if they harbor life.
(More space telescope stories.)