Nasa’s planet-hunting probe has found three confirmed exoplanets or worlds beyond our solar system where the third new planet is a whopping 23 times as massive as Earth.
The National Aeronautics and Space Administration (Nasa) which launched Transiting Exoplanet Survey Satellite (Tess) for searching exoplanets in April, 2018 has discovered a third small planet outside our solar system.
THE NEW PLANET
The new planet is named HD 21749b.
The newly discovered planet orbits a bright and nearby star which is about 53 light years away in the constellation Reticulum. HD 21749b appears to have the longest orbital period of the three planets so far identified by Tess. The surface of the new planet is hotter than 100 degrees Celsius.
The surface of HD 21749b is likely around 150 degrees Celsius, however, the surface is relatively cool given its proximity to its star, according to an IANS report. Why scientists are saying the new planet’s surface is relatively cool is because its star is almost as bright as our very own Sun, the team from the Massachusetts Institute of Technology in Boston said.
“It’s the coolest small planet that we know of around a star this bright,” lead researcher Diana Dragomir, a post-doctoral student at the MIT, said.
HD 21749b journeys around its star in a relatively leisurely 36 days, compared to the two other planets — Pi Mensae b, a “super-Earth” with a 6.3-day orbit, and LHS 3844b, a rocky world that speeds around its star in just 11 hours.
The planet is about three times the size of Earth, which puts it in the category of a “sub-Neptune”. It is also a whopping 23 times as massive as Earth.
But it is unlikely that the planet is rocky and therefore habitable; it’s more likely made of gas, of a kind that is much more dense than the atmospheres of either Neptune or Uranus.
“We think this planet wouldn’t be as gaseous as Neptune or Uranus, which are mostly hydrogen and really puffy. The planet likely has a density of water, or a thick atmosphere,” Dragomir said.
DISCOVERY OF ANOTHER PLANET
The boffins have also detected evidence of a second planet, though not yet confirmed, in the same planetary system, with a shorter, 7.8-day orbit, according to the IANS report.
If it is confirmed as a planet, it could be the first Earth-sized planet discovered by Tess.
The scientists announced the results at the annual American Astronomical Society meeting in Seattle.
Launched in April 2018 for a two-year mission, Tess will survey nearly the entire sky by monitoring and piecing together overlapping slices of the night sky.