Astronomers have discovered a Neptune-like exoplanet 90 light-years from Earth with an interesting atmosphere and possibly even water clouds. While that might not sound exciting, it is a big deal as it suggests the possibility of life elsewhere.
The discovery is a big step forward for exoplanet research, and it offers an ideal atmosphere for further study. It was discovered by an international group of collaborators at NASA’s Jet Propulsion Laboratory (JPL) and The University of New Mexico; the findings are due to be published in a future issue of The Astronomical Journal.
The exoplanet—a planet located outside of our own solar system—is called TOI-1231 b. Its rich atmosphere and gaseous state resemble that of Neptune, and it’s over 15 times more massive than Earth. It also orbits a red-dwarf star—NLTT 24399—that is smaller, dimmer, older, and less dense than our sun. TOI-1231 b completes an orbit in just 24 Earth days.
“Even though TOI-1231 b is eight times closer to its star than the Earth is to the Sun, its temperature is similar to that of Earth, thanks to its cooler and less bright host star,” stated Diana Dragomir, an exoplanetologist at The University of New Mexico and co-author of the study. “However, the planet itself is actually larger than Earth and a little bit smaller than Neptune—we would call it a sub-Neptune.”
The planet is also probably not habitable (at least not for humans), due to its size. Also, it is considerably colder than most other exoplanets we’ve discovered so far, averaging a balmy 134 degrees Fahrenheit, despite how closely it orbits its star. Planets with cooler temperatures like this often have clouds somewhere in their atmospheres, and now scientists will work to compare it with other exoplanets to figure out whether or not there are actually water clouds present.
Jennifer Burt—NASA JPL scientist, and the study’s lead author—said “TOI-1321 b is one of the only other planets we know of in a similar size and temperature range, so future observations of this new planet will let us determine just how common (or rare) it is for water clouds to form around these temperate worlds.”
Scientists used data from the Transiting Exoplanet Survey Satellite (TESS), which studies 200,000 of the brightest stars near our solar system. The satellite is able to help astronomers detect exoplanets by watching for transits, or moments where an exoplanet moves between us and its star, which is usually seen as a dip in brightness.
Additional research was conducted with the help of the Planet Finder Spectrograph (PFS) and the Magellan Clay telescope at Las Camapanas Observatory in Chile. The PFS is able to help detect exoplanets by focusing on the gravitational interaction with host stars, which tells us more about a body’s orbit and mass. The PFS is able to obtain its measurements by identifying stellar velocity variations.
Scientists are now awaiting information from the Hubble Space Telescope, which is set to study hydrogen emitting from TOI-1231 b’s atmosphere. And if the launch of the James Webb Telescope isn’t delayed any further beyond its current October schedule (knock on wood), it’ll be even easier for us to study exoplanets and their atmospheric composition
