Astronomy as we have never known it: NASA Discovered 2ND EARTH-SIZED PLANET IN THE HABITABLE ZONE.

NASA's Transiting Exoplanet Survey Satellite (TESS) has identified its first Earth-size planet in its star's habitable zone, the range of distances where circumstances may be just perfect to enable the existence of liquid water on the surface. Scientists validated the discovery, designated TOI 700 d, using NASA's Spitzer Space Telescope and have modeled the planet's probable habitats to assist and guide future studies. Credits: NASA's Goddard Space Flight Center\qpTESS watches wide regions of the sky, called sectors, for 27 days at a time. This lengthy gaze enables the satellite to follow variations in stellar brightness produced by an orbiting planet passing in front of its star from our viewpoint, an occurrence called a transit.