The hunt for another Earth is going to get a lot bigger. The Transiting Exoplanet Survey Satellite (TESS) is set to launch in 2017, NASA announced late last week. With a price tag of $200 million, TESS will be the first space-based mission to scan the entire sky for exoplanets, with a particular focus on small, rocky worlds around nearby stars.
TESS will be a successor to the Kepler space telescope, which has discovered more than 100 confirmed exoplanets and thousands of possible planets since its launch in 2009. Kepler has been staring 3000-light-years deep into a single patch of sky, looking for the tell-tale dips in starlight as a planet passes in front of – or transits – a star as seen from Earth. Although Kepler has not spotted one close to Earth yet, statistical analysis of the planets it has found suggests that the closest Earth-like world could be orbiting a star a mere 6.5 light years away.
TESS will also look for transiting planets, but it will use an array of wide-field cameras to scan roughly two million of the brightest and closest stars in our galactic neighbourhood. One of the mission’s goals will be to find Earth-size exoplanets in the habitable zone, the region around a star where liquid water can exist.
“Early results [from Kepler] indicate that TESS won’t have to look very far to find a world potentially like ours,” says Natalie Batalha, an astrophysicist and Kepler team member. “If they’re there – and Kepler tells us they should be – TESS will find them.” Via NASA’s next exoplanet hunter to launch in 2017