Although we have discovered over 5,000 exoplanets, or planets outside our solar system, most of these are not very Earth-like. They are often much larger than Earth, being more like the gas giants Saturn and Jupiter than small and rocky, and relatively few are in the habitable zone where liquid water could exist on their surface. That’s why it’s exciting when a planet comparable to Earth is discovered in its habitable zone, like one of those recently discovered planets.
The researchers observed a planet called LP 890-9b or TOI-4306b, previously discovered by NASA’s Transiting Exoplanet Survey Satellite. Using a ground-based telescope called SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars), they studied the planet, which is around 30% larger than Earth and orbits extremely close to its star, with a year lasting only 2, 7 days.
While the researchers were observing this planet, they also discovered another planet in the same system. This second planet, called LP 890-9c or SPECULOOS-2c, is about 40% larger than Earth and orbits farther from the star with an orbital period of 8.5 days. Because the star is much smaller and cooler than our sun, that puts this second planet within the habitable zone.
“This second planet receives about the same amount of stellar radiation as our Earth receives from the Sun, and therefore could have liquid water on its surface,” said one of the researchers, Robert Wells of the University of Bern, in a report. release. However, Wells cautions against assuming the planet would be comfortable for life based solely on its position. For example, in our solar system, Venus is close to being in the habitable zone, but it has extremely high temperatures and pressure on its surface, making it inhospitable to life.
To learn more about the newly discovered planet, researchers want to study it using the James Webb Space Telescope to look at its atmosphere and see if it really is potentially habitable.
“In order to answer whether or not this planet may contain liquid surface water, we need to learn more about it,” Wells said. “This requires detailed observations, for example with the James Webb Space Telescope.”
The research will be published in the journal Astronomy & Astrophysics.