NASA Discovers First Earth-Sized Planet In Star's Habitable Zone
In a landmark discovery, NASA's Transiting Exoplanet Survey Satellite (TESS) has found a roughly Earth-size planet in its host star's habitable zone, the range of orbital distances where conditions may be just right to allow the presence of liquid water on the surface.
The newfound exoplanet, TOI 700 d, is a small, cool M dwarf star (also known as a red dwarf) located just over 100 light-years away in the southern constellation Dorado. It's only 20% larger than Earth and completes one orbit every 37 days, scientists said.
"TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars," Paul Hertz, astrophysics division director at NASA Headquarters in Washington, said in a statement. "Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS.” TOI 700 d is one of only a few Earth-size planets discovered in a star's habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA's Kepler Space Telescope, the statement said. It's roughly 40% of the Sun's mass and size and about half its surface temperature. The star appears in 11 of the 13 sectors of the sky TESS observed during the mission's first year, and scientists caught multiple transits by its three planets. TESS, launched in April 2018, hunts for planets using the “transit method", monitoring large swaths of the sky, called sectors, for 27 days at a time and allowing the satellite to track changes in stellar brightness caused by an orbiting planet crossing stars’ faces from the satellite’s perspective.
Meet TOI-700d, the first Earth-sized planet in the habitable zone of another star found by @NASA_TESS Congrats @EmDwarf and @Astro_JRod (and the 100+coauthors!) pic.twitter.com/t26fKyVzPD
— Elisa Quintana (@elsisrad) January 7, 2020
"TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars," Paul Hertz, astrophysics division director at NASA Headquarters in Washington, said in a statement. "Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS.” TOI 700 d is one of only a few Earth-size planets discovered in a star's habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA's Kepler Space Telescope, the statement said. It's roughly 40% of the Sun's mass and size and about half its surface temperature. The star appears in 11 of the 13 sectors of the sky TESS observed during the mission's first year, and scientists caught multiple transits by its three planets. TESS, launched in April 2018, hunts for planets using the “transit method", monitoring large swaths of the sky, called sectors, for 27 days at a time and allowing the satellite to track changes in stellar brightness caused by an orbiting planet crossing stars’ faces from the satellite’s perspective.
Latest Videos
