About this world
TOI-700 d is an Earth-sized planet orbiting TOI-700, a cool red dwarf (type M2.5V) 102 light-years from Earth. It is about 1.1 times the size of Earth. It completes an orbit every 37.4 days at 0.16 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 269 K (−4 °C), which places it in the conservative habitable zone: the band where liquid water could exist on a rocky surface. By the "cosmic shoreline", it has likely held on to an atmosphere. Its atmosphere has already been studied in one spectroscopic observation by the James Webb Space Telescope.
It was discovered in 2020 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. TOI-700 has 4 known planets; the others are TOI-700 b, TOI-700 c and TOI-700 e.