NASA's planet-hunting spacecraft, Kepler, rocketed into space Friday night on a historic voyage to track down other Earths in a faraway patch of the Milky Way galaxy.
It's the first mission capable of answering the age-old question: Are other worlds like ours out there?
Kepler, named after the German 17th century astrophysicist, set off on its mission from Cape Canaveral at 10:49 p.m., thundering into a clear sky embellished by a waxing moon. Its mission will last at least 3 1/2 years and cost $600 million.
The goal is to find, if they're there, Earth-like planets circling stars in the so-called habitable zone — orbits where liquid water could be present on the surface of the planets. That would mean there are lots of places out there for life to evolve, said Kepler's principal scientist, Bill Borucki.
On the other hand, "if we don't find any, it really means Earths are very rare, we might be the only extant life."
Once it's settled into an Earth-trailing orbit around the sun, Kepler will stare at 100,000 stars near the Cygnus and Lyra constellations, between 600 and 3,000 light years away. The telescope will watch for any dimming in the stellar brightness that might be caused by orbiting planets.
Astronomers already have found more than 300 planets orbiting other stars, but they're largely inhospitable gas giants like Jupiter. Kepler will be looking for smaller rocky planets akin to Earth.
Kepler is designed to find hundreds of Earth-like planets if they're common and, perhaps, dozens of them in the habitable zone, Borucki said. The telescope is so powerful that from space, NASA maintains, it could detect someone in a small town turning off a porch light at night.
It won't be looking for signs of life, though. That's for future spacecraft.
Former chief of staff indicted: Courtney Stadd was indicted Friday on charges of steering $9.6 million in agency funds to a consulting client, Mississippi State University. Stadd is also accused of lying to NASA ethics officials investigating the matter. He faces up to 15 years in prison if convicted on all three charges. Stadd was with NASA from 2001 to 2003 and as a consultant for three months in 2005.
Shuttle launch set: After four delays, NASA has settled on a Wednesday night launch for space shuttle Discovery. Discovery will transport one final set of solar wings for the international space station.
weight in tons of President George W. Bush's official items transported by the Air Force to Lewisville, Texas, where it will stay until his presidential library opens at Southern Methodist University in Dallas in 2013.
presidential records, in cubic feet
audio-visual materials, in cubic feet
artifacts, including the 9mm pistol held by Saddam Hussein during his capture in 2003 and a 2004 World Series champion Red Sox jersey signed by the whole team
terabytes of electronic information transferred, or 100,000 gigabytes
long haul trucks used
airplanes used, two 747s and one DC-8