SnapGlow.TV: Bermuda Island Baby! After 20 years of being rejected by NASA, the scientists behind the new $600 million space telescope called Kepler saw redemption last week. The long-shot project, launched in March, proved in its first 10 days of work that it had the sensitivity to carry out its mission of finding other Earths.
While it hasn't found an Earth yet, the orbiting telescope did measure changes in the light of a distant star by a few parts per million - changes caused by a giant planet passing in front and then behind it. The findings were announced in last week's issue of the journal Science.
The planet, called HAT-P-7, had been detected before from ground, but Kepler tracked it with unprecedented precision, said principal investigator Jon Jenkins.
From the data Kepler beamed home, Jenkins said, he was able to chart the way the starlight dimmed as the planet passed in front of it, then brightened as it moved to the side, reflecting some starlight, then dimmed again as the planet passed behind.
Kepler is designed to detect planets this way, picking up the slight dimming effect of tiny eclipses created as the planets pass in front of their suns. To detect an Earth-size planet, the telescope would have to be able to measure a dip of just a few parts in a million, and Kepler's observations of HAT-P-7 show that's possible.
The planet, which lies more than 1,000 light-years away in the direction of the constellation Cygnus, is heated to about 2,500 degrees, Jenkins said. Its sun is more than twice as bright as ours, and it orbits closer than Mercury. It's also more than 300 times the mass of Earth.
Big planets are easier to find but unlikely to harbor life. Like Jupiter, most giant planets are thought to be mostly atmosphere with no solid surface on which to stand.
The Kepler scientists are monitoring a group of 100,000 stars, hoping to get a rough census on the number of Earth-size planets over the next three years.
- Faye Flam
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