NASA says it was able to use the James Webb telescope to take pictures of planet-forming disks around ancient stars, challenging theoretical models of planetary formation. These pictures support earlier findings from the Hubble telescope, which until now had not been confirmed.
Webb’s new highly detailed pictures were taken of the “Small Magellanic Cloud,” a dwarf galaxy neighboring our home, the Milky Way.
The Webb telescope focused in particular on a cluster called NGC 346, which NASA says is a good proxy for “similar conditions in the early, distant universe,” and which lacks heavy elements that have traditionally been associated with planet formation. Webb was able to capture a spectra of light that suggests protoplanetary disks are still hanging around those stars, contrary to previous expectations that they would have blown away in a few million years.
“Hubble observations of NGC 346 from the mid-2000s revealed many stars about 20 to 30 million years old that still have planet-forming disks,” NASA writes.
Without more detailed evidence, that idea was controversial. The Webb telescope was able to fill in those details, suggesting that disks in our neighboring galaxies have had much more time to collect the dust and gas that forms the basis of a new planet.
As for why those disks are able to persist in the first place, NASA says researchers have two possible theories. One is that the “radiation pressure” ejected from the stars in NGC 346 takes longer to eliminate planet-forming disks.
The other is that the larger gas cloud needed to form a “sun-like star” in an environment with fewer heavy elements would naturally form larger disks that take longer to fade away. Whichever theory proves to be correct, the new images are beautiful evidence that we still don’t have a full understanding of how planets form.