The dream of finding other habitable worlds like our own is now much closer to coming true thanks to the start of the Transiting Exoplanet Survey Satellite (TESS) mission.
The TESS satellite, launched yesterday, April 18, will scan more than 200,000 of the nearest, brightest stars for signs of exoplanets. Of the expected windfall of thousands of new planets, at least a hundred should be similar in size to Earth and located in their stars temperate “Goldilocks” zones, where water can stay liquid on a planet‘s surface.
TESS is led by the Massachusetts Institute of Technology (MIT). Many members of its MIT Kavli Institute (MKI) for Astrophysics and Space Research spearheaded TESS’ development and serve in primary roles on the mission. The Kavli Foundation, which endowed MKI, has supported the TESS mission as well.
To delve into the mission, The Kavli Foundation hosted a roundtable discussion with two MKI researchers involved with TESS. The conversation covered the motivations behind TESS and how it could discover the first-known “Earth twins” right in our cosmic neighborhood.
“TESS is going to find thousands of exoplanets, which might not sound like a big deal, because we already know of nearly 4,000,” said Diana Dragomir, an observational astronomer at MIT and MKI. “But most of those discovered planets are too far away for us to do anything more than just know their size and that they are there. The difference is that TESS will be looking for planets around stars very close to us. When stars are closer to us, they’re also brighter from our point of view, and that helps us discover and study the planets around them much more easily.”
When exoplanets cross the faces of their stars, they cause a slight dimming of the star’s luminosity. TESS is designed to pick this up. Other telescopes will then scrutinize the newly discovered worlds with sizes and masses similar to Earth’s–the candidates most likely to possess life-supporting environments.
Next-generation instruments, like the James Webb Space Telescope slated for a 2020 launch, will be able to detect the spectral “fingerprints” of gases in these exoplanets’ atmospheres. Those gases will reveal the exoplanet’s climate, history, and whether the world could be–or perhaps even is–an abode for alien life.
“One of the things TESS is doing is helping to answer the fundamental question, ‘Is there other life in the universe?'” said Greg Berthiaume, the TESS Instrument Manager at MKI and MIT’s Lincoln Lab. “People have been wondering that for thousands of years . . . That’s something we’ve been struggling with and questioning since we were able to come up with questions.”