A revolutionary impact
Thanks to our open policy and high data quality, the number and volume of TESS images and light curves downloaded from the Barbara A. Mikulski Archive for Space Telescopes (MAST) has been extraordinary. During 2020, users downloaded a total of 680 terabytes of data — about seven times the amount downloaded from either the Hubble or Kepler missions during that same period. In December 2020 alone, there were nearly 5 million requests for a total of about 50 TB of data.
During its 2019 review, NASA commended the TESS mission for “having a revolutionary impact on the fields of exoplanets and stellar astrophysics,” as well as for “providing a model of how to build and serve a broad user base to maximize science return.” As of March 2021, TESS had observed a total of 34 sectors and identified 2,597 TOIs. Of those, 755 have radii less than four times that of Earth and 120 are confirmed — thus far — as planets. Dozens more are underway.
The mission’s first planet, Pi Mensae c, is a super-Earth four times more massive and twice as large as Earth, circling the naked-eye Southern Hemisphere star Pi (π) Mensae every six days. But TESS has also discovered TOI-700 d — an Earth-sized planet orbiting in its red dwarf host star’s habitable zone, where conditions are right for a planet to maintain liquid water on its surface. And there’s also LHS 3844 b, a super-Earth so close to its star that one year lasts just 11 hours and daytime temperatures soar to 989 degrees Fahrenheit (531 degrees Celsius).
TESS’s data has provided observations for more than 300 scientific papers written in 2020 alone. And while most of those papers focus on new exoplanet discoveries, others are studies of the way stars vary, oscillate, spin, and produce flares. Citizen scientists can easily engage with TESS data through the Planet Hunters TESS Zooniverse project. This has led to the discovery of numerous planets, including TOI 1338 b — TESS’s first circumbinary planet with not one, but two suns at the center of its orbit.
Now engaged in its second complete survey of the full sky, this small but powerful satellite will continue to reveal the wide diversity of worlds — like and unlike our own — that share our solar neighborhood. Next, it will be up to missions like NASA’s JWST and Nancy Grace Roman Space Telescope, and the European Space Agency’s Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) satellite, to delve into this long list of nearby worlds in greater detail, studying their atmospheres and compositions to learn more about how exoplanets form and evolve. Perhaps one of these observatories will even hit the jackpot: discovering potential signs of life on a planet first identified by TESS.
George R. Ricker is principal investigator for the TESS mission. He also serves as director of the Detector Laboratory and is a senior research scientist at the MIT Kavli Institute for Astrophysics and Space Research.