NASA says newly discovered planet with 'unknown' atmosphere, strikingly similar to Earth

The discovery of a “cool” exoplanet located 90 light-years from Earth has excited scientists in their hunt for extraterrestrial life. According to a study published in Science Daily, researchers from NASA’s Jet Propulsion Laboratory and the University of New Mexico discovered exoplanet ‘TOI-1231 b’ orbiting an M dwarf star - otherwise known as a red dwarf. The scientists were able to characterise the star and measure both the radius and the mass of TOI-1231 b. 

As per the study, the researchers found that the planet, a temperate sub-Neptune-sized body with a 24-day orbit, is eight times closer to its star than the Earth is to the sun. But its temperature is similar to our home planet because the red dwarf itself is less potent, the team noted. They said that its atmosphere is approximately 330 Kelvin or 140 degrees Fahrenheit, making ‘TOI-1231 b’ one of the coolest, small exoplanets accessible for atmospheric studies discovered yet. 

The researchers said that the exoplanet has a low density, which suggests it is a gaseous planet rather than a rocky one like Earth. However, they added that they don’t yet know for certain the composition of the planet or its atmosphere. The researchers said that it is possible that there may be clouds high present high in the atmosphere and possible evidence of water. 

"TOI-1231 b is pretty similar in size and density to Neptune, so we think it has a similarly large, gaseous atmosphere," said lead study author Jennifer Burt, a postdoctoral fellow at NASA's Jet Propulsion Laboratory in Pasadena, California.

‘TOI-1231 b is positively frigid’ 

Assistant professor in UNM’s Department of Physics and Astronomy Diana Dragomir, added, “The low density of TOI 1231 b indicates that it is surrounded by a substantial atmosphere rather than being a rocky planet. But the composition and extent of this atmosphere are unknown”. Dragomir said explained that TOI1231 b could have large hydrogen or hydrogen-helium atmosphere, or a denser water vapour atmosphere. Each of these would point to a different origin, allowing astronomers to understand whether and how planets form differently around M dwarfs when compared to the planets around our Sun, he said. 

Further, Burt said, “One of the most intriguing results of the last two decades of exoplanet science is that, thus far, none of the new planetary systems we’ve discovered look anything like our own solar system”. 

He added, “They’re full of planets between the size of Earth and Neptune on orbits much shorter than Mercury’s, so we don’t have any local examples to compare them to. This new planet we’ve discovered is still weird - but it’s one step closer to being somewhat like our neighbourhood planets. Compared to most transiting planets detected thus far, which often have scorching temperatures in the many hundreds or thousands of degrees, TOI-1231 b is positively frigid”. 

 (Image: NASA/Website)