In the five years since its launch, the Kepler space telescope has discovered thousands of possible planets, including a confirmed three-planet system known as KOI-961, shown here in an artist's concept. The three planets are all closer to their star than Mercury, the innermost planet in the solar system, is to the Sun. All three planets are smaller than Earth. Because they are so close to their parent star, however, they are unlikely to host life. [NASA/JPL]
The star system Kepler 90 is like a compact version of our own solar system. The star itself is quite similar to the Sun. And it’s encircled by a family of at least seven planets — none of which is farther from the star than Earth is from the Sun. It’s the largest planetary family yet seen beyond the solar system.
The planets were discovered by one of the most productive space telescopes in history.
NASA PAO: One, zero, and liftoff of the Delta II rocket with Kepler, on a search for planets in some way like our own...
Kepler was launched five years ago this week. Its main mission was to hunt for Earth-sized planets orbiting Sun-like stars. Along the way, it was expected to find thousands of planets of all kinds, helping scientists begin to understand how planets form — and the likelihood that some planets might be inhabited.
Kepler stared non-stop at 150,000 stars in a small patch of sky. It looked for the stars to dim a tiny amount as planets passed directly in front of them. Kepler’s observations, combined with follow-up work from the ground, could reveal a planet’s size and mass, its distance from its star, and more.
Kepler has found more than 3500 possible planets. Last year, though, an equipment failure left the spacecraft unable to maintain its precise fix on the sky, so it could no longer hunt planets. But engineers have a plan that could put Kepler back in business — looking for worlds beyond our own solar system.
More about Kepler tomorrow.
Script by Damond Benningfield, Copyright 2014
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