NASA found what is likely a water planet not too far from our solar system.
An exoplanet that is three times the size of Earth was identified in a start system approximately 53 light-years away by NASA’s Transiting Exoplanet Survey Satellite (TESS), a telescope that’s been scanning the skies for exoplanets for three months.
The new planet, which is called HD 21749b, was announced on January 7. Despite its size, HD 21749b has 23 times the mass of the Earth, which leads scientists to believe that it’s a gaseous planet 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 explained. “The planet likely has a density of water, or a thick atmosphere.”
HD21749b likely has a surface temperature of approximately 300°F, which is a surprisingly cool temperature for how close the planet is to its star, which scientists say is comparable to our sun. It orbits its star every 36 days, compared to the other two exoplanets that TESS has identified.
“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.