spaceSpace and Physics

NASA Is About To Launch Its Next Great Planet-Hunting Telescope


Jonathan O'Callaghan

Senior Staff Writer

TESS is expected to find thousands of planets beyond the Solar System. NASA/GSFC

If you aren’t excited about NASA’s next science launch in a week’s time, you really should be. Because it is shaping up to be one of the most important missions of the decade.

The Transiting Exoplanet Survey Satellite, or TESS, is scheduled to launch on Monday, April 16 from Cape Canaveral in Florida on a SpaceX Falcon 9 rocket, the first NASA science launch for Elon’s company.


But for once, all eyes won’t be focused on the Falcon 9. Because TESS is a planet-hunter like no other, designed to find Earth-like worlds elsewhere in the galaxy.

“We expect TESS will discover a number of planets whose atmospheric compositions, which hold potential clues to the presence of life, could be precisely measured by future observers,” George Ricker, the principal investigator (PI) for the mission, said in a statement.

TESS is a follow-up to NASA’s wildly successful Kepler mission. Launched in 2009, that space telescope has since found thousands of worlds beyond our Solar System (exoplanets). In mere months, however, the mission is expected to come to an end – with TESS poised to grab the mantle.

Using four wide-field cameras, TESS will observe about 85 percent of the entire sky from quite an odd orbit (see below), split into 26 different sectors with 13 for each hemisphere. It’ll look for planets by noticing the dip in a star’s light as planets pass in front, known as a transit, the same method used by Kepler.


While Kepler looked at a range of stars, however, TESS will be focusing on those that are smaller and cooler than our own Sun, such as M dwarfs and K dwarfs. For this reason it probably won’t find planets exactly like our own, in the same orbit around similar stars, but it will still give us a great idea of how many potentially habitable planets are out there.

“I don’t think we know everything TESS is going to accomplish,” TESS project scientist Stephen Rinehart said in the statement. “To me, the most exciting part of any mission is the unexpected result, the one that nobody saw coming.”

Many of the planets discovered by TESS will be prime targets for future missions, like the constantly delayed James Webb Space Telescope (JWST), to study their atmospheres. It will focus on planets 30 to 300 light-years away, close enough for follow-up study.

The primary mission of TESS is expected to last two years, although there’s always the chance it’ll be extended. As we say goodbye to Kepler, we say hello to our next great planet-hunter, which should keep us entertained and busy for a good few years. Who knows what secrets about Earth-like or other worlds it is waiting to uncover.


spaceSpace and Physics
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  • exoplanets,

  • nasa,

  • earth,

  • JWST,

  • TESS,

  • Earth-like,

  • search for life