Exoplanets

TESS has recently found a new Earth-like planet around the star TOI 700. TOI stands for Tess Object of Interest. This is the first discovery of an Earth-like planet done by TESS. The star has three planets called TOI 700 b,TOI 700 c,TOI 700 d. The first planet is TOI 700 b that has the same size as Earth but is very hot and is more like an Earth-size Mercury. The second planet is a Super-Earth eight times the size of Earth. The planet is too hot and would be more like a Super Venus. The third planet is a little larger than Earth with 1.7 the mass of Earth and is in the inner edge of the habitable zone of the star. Technically the planet could have liquid water and support life. The planet would not be an Earth twin as it orbiting an M type star a red dwarf with 40 percent of the mass of our Sun. All the planets will probably have tidally locked orbits were one side of the planet would always face the star and be hot and the other side never gets any light from the star and is cold. Perhaps humans could survive in the area between the cold and hot part of TOI 700 d if the planet has a correct atmosphere. 

Image credit: NASA's Goddard Space Flight Center

A problem with red dwarf stars is that they usually have violent flares that could strip any planet of its atmosphere. The good news is that TOI 700 does not show a single flare. There are several indications that the star has low stellar activity and simulations of the planet have shown that it is a strong candidate for being a habitable world. We can not be sure if the star had higher stellar activity and flares in the past. The discovery was also confirmed by NASA’s Spitzer Space Telescope. TOI 700 is located 100 light-years from Earth in the Dorado constellation. We will not be able to visit soon, but next year when James Webb telescope is in use that has a sharper instrument we can receive more information about the composition of the planet.