WASHINGTON — NASA's Transiting Exoplanet Survey Satellite, or 'TESS' mission, devised to specifically find Earth-sized planets orbiting nearby stars has identified TOI 700 d as a potential candidate occupying a star's habitable zone where conditions may be just right to allow the presence of liquid water on the surface.<br /><br />NASA explains that TESS observes large regions of the sky known as sectors for 27 days at a time. TESS identifies and tracks changes in stellar brightness caused by an orbiting planet passing in front of its star.<br /><br />During recent observations, TESS tracked a total of three planets.<br /><br />The closest to the star, TOI 700 b is Earth-sized, rocky and has an orbit of ten days. The middle planet, TOI 700 c, is 2.6 times larger than Earth, likely gas-dominated and orbits every 16 days. TOI 700 d, the only one in the habitable zone, measures 20 percent larger than Earth and orbits every 37 days.<br /><br />While the exact conditions on TOI 700 d are unknown, researchers at NASA's Goddard Space Flight Center created models to explore its potential conditions to help narrow future predictions of the planet's atmosphere. One model showed a water-covered world and the other, a completely dry version of today's earth. <br /><br />NASA says that future missions, "may be able to identify whether the planets have atmospheres and, if so, even determine their compositions."
