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New planet-hunter gets go-ahead from NASA

Paul Sutherland, Feature writer
Apr 8, 2013, 7:00 UTC

Sen—NASA is to launch a new planet-seeking spacecraft that will seek out planets as small as rocky worlds like the Earth.

TESS—the Transiting Exoplanet Survey Satellite—will add to the incredible success enjoyed by the agency’s Kepler space telescope that has detected well over a hundred confirmed new worlds since its launch in 2009 plus 2,740 possibles that still need to be confirmed.

Kepler does this by gazing constantly at a small patch of sky in the constellations of Cygnus and Lyra to catch any slight dimming due to a planet passing in front of it—called a transit.

TESS will be able to use an array of telescopes to scan the whole of the sky rather than just one patch. It promises to mop up many more transiting exoplanets from gas giants like Jupiter right down to those the size of Earth.

The project has been selected by NASA as one of the latest two missions to be launched in 2017. The other is an X-ray instrument called the Neutron Star Interior Composition Explorer (NICER) that will be mounted on the International Space Station.

Looking like a box with an array of 56 telescopes, it aims to learn more about the exotic states of matter inside these incredibly dense objects where a teaspoon of matter can weigh a billion tons. We’ll tell you more about the NICER mission tomorrow!

The two missions had been shortlisted in 2011 from a number of proposals. They will be the latest in a program that has launched more than 90 missions beginning in 1958 with Explorer 1 which discovered the Earth’s radiation belts.

TESS’s scientists, based at the Massachusetts Institute of Technology, are especially keen to identify terrestrial planets orbiting in their stars’ habitable zones where liquid water can exist.

Exoplanet in transit

Artwork showing an exoplanet passing in transit across the face of its star, blocking out a fraction of its light. Credit: NASA, ESA and G. Bacon

The team, led by George Ricker, say that while Kepler has found many smaller exoplanets, the stars it watches are faint and difficult to study. TESS will examine a large number of small planets around the very brightest stars in the sky. Its onboard telescopes might even be able to spot multiple planets around a single star.

Ricker said: “TESS will carry out the first-ever spaceborne all-sky transit survey, covering 400 times as much sky as any previous mission. It will identify thousands of new planets orbiting a broad range of stellar types, and with widely varying distances from their host star.”

John Grunsfeld, NASA’s associate administrator for science, said: “The Explorer Program has a long and stellar history of deploying truly innovative missions to study some of the most exciting questions in space science.”