NASA satellite discovers second Earth-sized planet in habitable zone

Scientists from NASA announced Tuesday that they discovered an Earth-size planet orbiting its star's habitable zone.

Called TOI 700 e, the planet is part of the TOI 700 system and is 95% the Earth's size and likely rocky, according to NASA, which used data from its Transiting Exoplanet Survey Satellite (TESS).

"This is one of only a few systems with multiple, small, habitable-zone planets that we know of," Emily Gilbert, a postdoctoral fellow at NASA's Jet Propulsion Laboratory in Southern California who led the work, said in a statement on NASA's website.

NASA previously discovered three planets in the same system, called TOI 700 b, c and d. Planet d is also in the habitable zone of the star, NASA said.

"Planet e is about 10% smaller than planet d, so the system also shows how additional TESS observations help us find smaller and smaller worlds," Gilbert said.

Paul Hertz, a senior advisor to the Associate Administrator of the Science Mission Directorate, said in 2020 that "TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars."

TOI 700 e takes 28 days to orbit its star called TOI 700, a small red dwarf star located around 100 light-years from Earth.

In 2020, a New York teenager interning at NASA discovered a planet 6.9 times larger than Earth that orbited two stars, what scientists call a circumbinary planet.

NASA said the Wolf Cukier’s discovery was rare because circumbinary planets, which are usually difficult to find and scientists can only detect these planets during a transit event, when one of the suns shows a decrease in brightness.

ABC News' Ivan Pereira contributed to this report.