James Webb telescope spots 6 enormous 'rogue planets' tumbling through space without a star

The James Webb Space Telescope (JWST) has spotted six rogue planets drifting freely through space, untethered from the gravity of any companion stars.

The planets are wandering through the Perseus molecular cloud 960 light-years away and range in size from five to 10 times the mass of Jupiter.

The strange cosmic vagabonds are evidence that gigantic planets can form in much the same way as stars — congealing directly from turbulent clouds of collapsing interstellar gas, scientists said. The researchers' findings have been accepted for publication in The Astronomical Journal and are available on the preprint server arXiv.

"We are probing the very limits of the star forming process," study lead author Adam Langeveld, an astrophysicist at Johns Hopkins University, said in a statement. "If you have an object that looks like a young Jupiter, is it possible that it could have become a star under the right conditions? This is important context for understanding both star and planet formation."

Typically, planets form from the leftover gas and dust used in the formation of stars, creating solar systems such as our own. But not every planet is made by this process: Sometimes gigantic planets can form directly from gas collapse, the study authors said.

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To spot the wanderers, the researchers used the JWST's Near Infrared Imager and Slitless Spectrograph (NIRISS) to peer through the billowing gas clouds and analyze the infrared light profile of every object in the observable portion of the star cluster. Using this method, the researchers also spotted a number of known brown dwarfs — strange objects that are more massive than the largest planets but smaller than the smallest stars — including one accompanied by a planet-size object.