TESS Mission's First Earth-size World in Star's Habitable-zone

NASA's Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star's habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA's Spitzer Space Telescope and have modeled the planet's potential environments to help inform future observations. TOI 700 is a small, cool M dwarf star located just over 100 light-years away in the southern const