NASA's satellite discovers Earth-size world

U.S. scientists have identified an Earth-size world using data from NASA's Transiting Exoplanet Survey Satellite (TESS), NASA announced on Tuesday.

The planet, called TOI 700 e, is 95 percent Earth's size and likely rocky.

Astronomers previously discovered three planets in this system, called TOI 700 b, c, and d. Scientists needed an additional year of TESS observations to discover TOI 700 e.

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

"That makes the TOI 700 system an exciting prospect for additional follow up. Planet e is about 10 percent smaller than planet d, so the system also shows how additional TESS observations help us find smaller and smaller worlds," Gilbert said.

"TESS just completed its second year of northern sky observations," said TESS deputy project scientist Allison Youngblood. "We're looking forward to the other exciting discoveries hidden in the mission's treasure trove of data."