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NASA launches another planet hunter

March 20, 2018

NASA launches its Transiting Exoplanet Survey Satellite (TESS) mission from Cape Canaveral in Florida on a SpaceX Falcon 9 rocket, aiming to identify planets that are orbiting stars outside the solar system. NASA’s Kepler space observatory is also hunting planets, but it lacks the keen “eyes” and vast scope of TESS.

The aim is to identify extrasolar planets, ranging from Earth-sized bodies to gas giants, with particularly interest in the rocky worlds in the habitable zones of their host stars.

Like the Kepler probe, TESS will look for planets as they pass in front of distant stars and slightly dim the stars’ light. But TESS will study stars throughout the entire night sky, expanding Kepler’s limited range. Each TESS camera has a field of view that is more than five times greater than Kepler’s camera.

“The instantaneous field of view of the TESS cameras, combined with their area and detector sensitivity, is unprecedented in a space mission,” according to TESS Principal Investigator George Ricker.

The satellite’s four cameras, developed by researchers at MIT’s Kavli Institute for Astrophysics and Space Research and the MIT Lincoln Laboratory, are equipped with large-aperture wide-angle lenses designed to survey the entire sky, but they have an innate limitation: the image sharpness varies over the field of view, and there is no single focus, as found in more conventional cameras. And in TESS cameras, the imaging properties change as the temperature of the cameras changes. The MIT TESS team and NASA have concluded independently that the limitation will not prevent the mission from achieving its scientific goals.

#22457 Published: January 5, 2018