Astronomers find salt clouds in atmosphere of distant Pink Planet

Researchers studying the universe's Pink Planet have found clouds made of salt in its atmosphere.

A team of astronomers led by Northwestern University used the James Webb Space Telescope to identify a salty cloud layer unlike any previously observed. The findings were published Thursday in The Astronomical Journal.

The object, formally known as GJ504b, was discovered in 2013. It is described as a planetary-mass companion because it could be either a giant exoplanet or a small brown dwarf orbiting a star, according to Northwestern.

It orbits a sun-like star 57 light-years from Earth. Its temperature is 550 degrees Fahrenheit, hot by Earth standards but far colder than most giant planets, which usually range from 1,000 to 2,000 degrees, the university said.

"We were very surprised, because people have theorized that salt clouds might exist in the atmospheres of companions at these temperatures of, say, 500 to 700 degrees Fahrenheit, but people in general just don't observe any kind of signatures of clouds in such temperatures, so we were very surprised," Aneesh Baburaj, the leader of the study, told CBS News.

The companion is estimated to be 25 times the mass of Jupiter and between 2.5 billion and 4 billion years old. Its age explains the lower temperature, since giant planets cool as they age, Baburaj said. He is a postdoctoral associate at Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics.

Its low temperature has made observations from Earth difficult. Multiple teams worldwide have tried and failed to detect its light, Baburaj said. With the Webb telescope, researchers completed a successful observation in two hours.

The telescope records infrared images and spectra that spread light to reveal chemical fingerprints. After capturing the object's faint light, the team produced a spectrum that showed water vapor, methane, carbon dioxide, ammonia and other molecules. The data only matched models when salt clouds were included, indicating the clouds were altering the light reaching the telescope.

"We were really, really amazed by how easy it was to detect with James Webb, as opposed to like it had been close to impossible from the ground," Baburaj told CBS News.

He said salt clouds occupy a middle range in planetary atmospheres. On Earth, clouds are made of water. On Jupiter, they are made of ammonia. Hotter worlds can have clouds of silicates. Salt clouds form in conditions too hot for water or ammonia clouds and too cool for silicate clouds.

Baburaj added that the Webb telescope's greater power will allow astronomers to study colder objects that may have higher metal-to-hydrogen ratios than the sun.