NASA's TESS identifies new exoplanet thrice the size of Earth

NASA has found a planet that is likely to have water and isn't too far from our planet. The exoplanet is thrice the size of our Earth and is said to be 53 light-years away according to NASA's Transiting Exoplanet Survey Satellite (TESS).

Dubbed HD 21749b, the new planet was announced on January 7. Although it's thrice the size of our planet, it is 23 times heavier when talking of the mass. This leads the scientists to believe that the exoplanet is gaseous and not rocky, like Earth.

"We think this planet wouldn't be as gaseous as Neptune or Uranus, which are mostly hydrogen and really puffy," MIT researcher Diana Dragomir said. "The planet likely has a density of water or a thick atmosphere."

The HD21749b has a surface temperature of approximately 300°F, which is surprising considering the distance between the star and the planet. The planet orbits the star every 36 days, compared to other two exoplanets that TESS has earlier found.

"We know a lot about atmospheres of hot planets, but because it's very hard to find small planets that orbit farther from their stars and are therefore cooler, we haven't been able to learn much about these smaller, cooler planets," Dragomir said.

Previously, NASA discovered a planet called +K2-288Bb, which is located within its star's habitable zone, hinting a possibility of liquid water. Its size is different from other exoplanets that revolve around a star outside our solar system. Few planets that orbit close to their stars are more than 1.5 times as large as Earth, yet K2-288Bb is said to be around 1.9 times bigger than the size of our planet.