Nearly 100 rogue, glow-in-the-dark planets are floating in our galaxy, scientists find
Using data from the European Southern Observatory telescopes, scientists spotted something: dozens of previously undiscovered planets floating around the galaxy, with nowhere in particular to go.
While it may be another speck in the ether to an untrained eye, it was one of the most exciting discoveries the team stumbled across, Núria Miret-Roig, an astronomer and the first author of the new study published Dec. 22 in the journal Nature Astronomy, said.
“We did not know how many to expect and are excited to have found so many,” she said in a news release about the discovery.
The scientists found at least 70 rogue planets in the galaxy, the largest discovered group of its kind in history. They had similar mass to Jupiter and were found in the star-forming region close to our Sun, researchers reported.
“This is the largest group of rogue planets ever discovered, an important step towards understanding the origins and features of these mysterious galactic nomads,” the observatory said in a statement.
Rogue planets get their name because they don’t have orbits and simply meander through space without being tethered to a certain area. The team of scientists used data from over 20 years from telescopes to spot the cluster of rogue planets, but there was another factor that made it possible for astronomers to find them, according to the observatory.
The planets don’t just roam. They also glow.
Since the planets are rogue, there aren’t any stars illuminating them, posing challenges to researchers when looking for them. However, the team at the observatory was able to utilize the fact that the planets they were searching for were still relatively young, the release said, and were still hot.
The heat coming off the planets gave them a certain glow, which made it possible to pinpoint them from a far distance in the dark.
The researchers used cameras on the observatory’s Very Large Telescope and Visible and Infrared Survey Telescope for Astronomy telescopes, among others, to find the planets. It also used the European Space Agency’s Gaia satellite, which was a milestone for space- and ground-based telescope cooperation.
While the recent discovery was the largest to date, there is evidence to suggest that there could be an overwhelming number of rogue planets throughout the galaxy, the scientists said.
“There could be several billions of these free-floating giant planets roaming freely in the Milky Way without a host star,” Hervé Bouy, an astronomer and research project leader, said in the release.
Moving forward, the team said it hopes to unlock the mystery of the rogue planets and how they form by studying them more in detail through the telescopes at the European Southern Observatory and in other locations. One major advantage in examining rogue planets will be the Extremely Large Telescope in the Chilean Atacama Desert, which will be in commission for observations later this decade, the release said.
“These objects are extremely faint and little can be done to study them with current facilities,” Bouy said. “The ELT will be absolutely crucial to gathering more information about most of the rogue planets we have found.”
This story was originally published December 28, 2021 at 5:41 PM.
