Astronomers find 2nd Earth-size planet in intriguing alien solar system

NASA's leading planet-hunting spacecraft has spotted its second planet that matches Earth's size and may be able to retain liquid water — and both worlds orbit the same star.
NASA's Transiting Exoplanet Survey Satellite (TESS) launched in April 2018; since then, the mission has discovered 285 confirmed exoplanets and more than 6,000 candidates. One of the most intriguing of the confirmed planets is a world dubbed TOI 700 d, which is about the size of Earth and located in its star's habitable zone. Now, scientists have determined that the planet has a neighbor that's just as tantalizing, thanks to an October 2021 alert that the Earth-orbiting telescope had seen something interesting.
Astronomers find 2nd Earth-size planet in intriguing alien solar system