NASA's 'TESS' Discovers Its First Earth-Size Habitable-Zone World
NASA ’s Transiting Exoplanet Survey Satellite (TESS) has found its first Earth-size planet in its star’s habitable zone – the range of distances where conditions might allow for the presence of liquid water on the surface. The discovery, called TOI 700 d, was confirmed by scientists using NASA’s Spitzer Space Telescope. The scientists have modeled the planet’s potential environments to help inform future observations. 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. TOI 700 is a small, cool M dwarf star that is located a little over 100 light-years away in the southern constellation Dorado. The innermost planet, TOI 700 b, is almost exactly Earth-size.