The area where the discovery occurred was identified as habitable.
The planet is called “TOI 700 d” and is relatively close to Earth, a hundred light-years away, the US space agency said.
The discovery belonged to the TESS satellite, “designed and launched specifically to find Earth-sized planets and orbiting nearby stars”, said Paul Hertz who is the director of NASA’s astrophysics division.
Some other similar planets have been discovered before, mainly by the old Kepler space telescope, but this is the first of TESS, launched in 2018.
TESS discovered three orbiting planets called “TOI 700 b”, “c” and “d”.
Only the “d” is in the so-called habitable zone. It is almost the size of the Earth (20% more), circulates the star in 37 days and receives 86% of the energy supplied by the Sun to Earth.
The researchers generated models based on the size and type of the star to predict atmosphere composition and surface temperature.
One of the simulations, NASA said, points to a planet covered by oceans with “a dense atmosphere dominated by carbon dioxide, similar to Mars ‘appearance at a young age, according to scientists’ assumptions.”
A face of this planet always faces its star, as is the case of the moon with the earth, a phenomenon called synchronous rotation. This face would be constantly covered with clouds, according to this model.
Another simulation predicts an earth less version of the Earth, where winds would blow from the hidden side toward the illuminated face. Several astronomers are now observing the planet with other instruments, trying to get new data that could match one of NASA’s predicted models.