Astronomers have suspected for a long time that this is how larger planets—like Jupiter in our own Solar System—get their moons.
Now a team of astronomers have spotted this circumplanetary disk, and moons forming in it, for the first time.
“Planets form from disks of gas and dust around newly forming stars, and if a planet is large enough, it can form its own disk as it gathers material in its orbit around the star,” Isella said.
That star was in the news about a year ago when astronomers captured the first-ever image of a newly-forming planet in a circumstellar disk.
“For the first time, we can conclusively see the telltale signs of a circumplanetary disk, which helps to support many of the current theories of planet formation,” said Andrea Isella, lead author.
“This means we’ll be able to come back to this system at different time periods and more easily map the orbit of the planets and the concentration of dust in the system,” concluded Isella.
From the study: “As ALMA and existing optical telescopes are reaching their full imaging capabilities, forthcoming observations of nearby circumstellar disks characterized by cavities and gaps like those observed in PDS 70 might reveal more newborn planets interacting with their natal disk.