TOI 700 d: Earth-sized planet found relatively nearby

TOI 700 d: Earth-sized planet found relatively nearby

NASA has announced that its planet hunter satellite TESS discovered an Earth-sized world within the habitable range of its star, which could allow the presence of liquid water.

The planet, named "TOI 700 d", is relatively close to Earth: only 100 light-years away, NASA's Jet Propulsion Laboratory said on Monday during the annual American Astronomical Society meeting in Honolulu, Hawaii.

"TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars," said Paul Hertz, NASA astrophysics division director.

TESS initially misclassified the star, which meant the planets appeared larger and hotter than they actually are. But several amateur astronomers, including high school student Alton Spencer - who works with members of the TESS team - identified the error.

"When we corrected the star's parameters, the sizes of its planets dropped, and we realized the outermost one was about the size of Earth and in the habitable zone," said Emily Gilbert, a graduate student at the University of Chicago.

The discovery was later confirmed by the Spitzer Space Telescope.