Kepler lifts off Friday night in Florida.
(Credit: NASA/Jack Pfaller )The Kepler spacecraft vaulted away from Cape Canaveral late Friday, boosting a powerful space telescope into orbit around the sun for a $591 million mission to search for Earth-like planets orbiting distant stars.
"I think people everywhere want to know whether, with all the stars out there, do they have planets that are Earth-sized?" said principal investigator William Borucki of NASA's Ames Research Center. "Are Earths frequent or are they rare? And this gives us that answer. It's the next step in mankind's exploration of the galaxy."
The Kepler spacecraft's three-and-a-half-year mission began on time at 10:49:57 p.m. local time with a crackling roar and a torrent of fire that briefly turned night into day along Florida's coast.
This was the 339th Delta rocket launched since 1960, the 141st upgraded Delta 2 rocket, and the 86th successful Delta launch in a row dating back to January 1997. The Delta 2 record now stands at 139 successful missions against just two failures.
Engineers will spend about two months checking out and calibrating Kepler's complex systems before the mission begins in earnest.
Trailing the Earth in its orbit around the sun, Kepler will aim a 95-megapixel camera on a patch of sky the size of an outstretched hand that contains more than 4.5 million detectable stars. Of that total, the science team has picked some 300,000 that are of the right age, composition, and brightness to host Earth-like planets. Over the life of the mission, more than 100,000 of those will be actively monitored by Kepler.
The spacecraft's camera will not take pictures like other space telescopes. Instead, it will act as a photometer, continually monitoring the brightness of candidate stars in its wide field of view and the slight dimming that will result if planets happen to pass in front.
By studying subtle changes in brightness from such planetary transits and the timing of repeated cycles, scientists can ferret out potential Earth-like worlds in habitable-zone orbits.
The probability of finding sun-like stars with Earth-like planets in orbits similar to ours--and aligned so that Kepler can "see" them--is about one-half of 1 percent. Given the sample size, however, that still leaves hundreds of potential discoveries.
But it will take three-and-a-half years of around-the-clock observations to capture the repeated cycles needed to confirm detection of an Earth-like world in an Earth-like orbit.
"There's a lot of desire in the science community to understand extraterrestrial planets, not just find them," said Ed Weiler, NASA's associate administrator for space science. "We've already found 300 or so, mostly from the ground. But now we're entering the stage of going beyond just proving that they exist. It's how many are out there, and perhaps the most important question of all, are there any 'Earths' out there?"
The original version of this article by CBS News space consultant William Harwood can be found here.
NASA's Kepler satellite will scope out a section of the Milky Way in hopes of finding planets similar to Earth.
(Credit: NASA/JPL)In the vastness of the universe, there are likely to be nearly countless planets. The big question for humans, of course, is whether even a single one of them could support life.
NASA's Kepler satellite, which is scheduled to lift off at 10:49 p.m. EST tonight, is headed out to keep watch on a patch of the Milky Way for at least three and a half years. Unlike the Hubble space telescope, Kepler won't be taking brilliant pictures suitable for framing. Instead, it will look for minute changes in the brightness of stars--some 100,000 of them--that would indicate a planet passing in front.
Of all the planets Kepler eventually finds, what NASA is most interested in are planets like Earth. That is, it's looking for rocky orbs--from half as large to twice as large as our big blue marble--in the habitable zone around a given star where conditions might be amenable to folks like us, or at least some of our fellow earthly organisms.
"The habitable zone is where we think water will be," Bill Borucki, Kepler principal investigator at NASA Ames, says in a video on the space agency's Kepler site. "If you can find liquid water on the surface we think we may very well find life there. So that zone is not too close to the star, because it's too hot and water boils, and not too far away where the water is condensed...a planet covered with glaciers. It's the Goldilocks zone--not too hot, not too cold, just right for life."
To scope out the interstellar terrain, Kepler will use its photometer--essentially, an oversize light meter--equipped with 42 charged coupled devices, or CCDs. Your digital camera uses CCDs, too, though they're much smaller. And where your pocketable camera might be rated at 8 megapixels, Kepler's telescope weighs in at 95 megapixels.
Kepler's unblinking eye will scan a wider area than most astronomical telescopes, according to NASA. Where those devices see an area equivalent to a grain of salt held at arm's length, Kepler sees the whole hand at that distance.
According to a report issued this week by the Government Accountability Office, the Kepler project's total cost as of December was $595 million. Yes, that's more than was originally budgeted for it, and yes, it's launching about nine months behind schedule.
But for the moment, let bygones be bygones. Friday morning, NASA reported that the weather forecast in Florida is auspicious for tonight's launch: a 95 percent chance of favorable conditions, with a temperature of 64 degrees.
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