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Planet Hunter

March 20, 2018

The next planet hunter is getting ready for launch. It’ll sweep the skies within a few hundred light-years of Earth. Astronomers say its discoveries could include a few hundred worlds that are similar to Earth — about the same size, and at the right distance from their stars to support life.

TESS — the Transiting Exoplanet Survey Satellite — will use the same technique used by Kepler, a small space telescope that’s discovered thousands of confirmed or possible planets. It will monitor the light of several hundred thousand stars. If a planet passes in front of a star, the star will get a bit fainter for a while. Just how faint will reveal the size of the planet.

While Kepler concentrated on a single small patch of sky for much of its mission, TESS will scan almost the entire sky. Its cameras will monitor bright stars that are fairly close. That will make it easier to study any planets it discovers using other telescopes in space and on the ground. The follow-up observations can provide a thorough dossier on a planet, including whether it has an atmosphere, and the atmosphere’s composition.

TESS’s cameras will scan 26 patches of the sky for about a month at a time. They’ll begin with the southern hemisphere, then move to the north a year later.

If TESS works as planned, it could add hundreds or thousands of worlds to the list of known exoplanets — including some that could be among our closest neighbors in the entire galaxy.

Script by Damond Benningfield

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