Using the Transiting Exoplanet Survey Satellite (TESS), NASA has discovered a habitable planet the size of Earth orbiting a star.
The habitable planet orbits a star in the range of distances at which conditions may allow the presence of liquid water on its surface.
According to a statement from NASA, scientists confirmed the discovery, called the TOI 700 d, using NASA’s Spitzer Space Telescope. NASA also said the TOI 700 d is one of the few Earth-sized planets discovered in a star’s habitable zone so far.
Others include various planets in the TRAPPIST-1 system and other worlds discovered by NASA’s Kepler Space Telescope.
TOI 700 is a small, fresh M dwarf star located just over 100 light years away in the southern constellation of Dorado. It is about 40% of the mass and size of the sun and about half the surface temperature. The star appears in 11 of the 13 sectors observed by TESS during the first year of the mission, and scientists captured several transits from its three planets.
The star was originally misclassified in the TESS database as being more similar to our Sun, which meant that the planets looked bigger and hotter than they really are. Several researchers, including Alton Spencer, a high school student who works with TESS team members, have identified the error.
Emily Gilbert, a graduate student at the University of Chicago, said:
When we corrected the parameters of the star, the sizes of its planets dropped and we realized that the outermost was the size of the earth and the habitable zone.
Additionally, in 11 months of data, we saw no star bursts, which increases the chances of the TOI 700 d being habitable and facilitates modeling of its atmospheric and surface conditions.
It is worth mentioning here that the TESS satellite monitors sectors of the sky for 27 days at a time, allowing the satellite to track changes in the brightness of a star caused by an orbiting planet crossing in front of it.