Exomoon Formation Spotted for First Time!

Using ALMA, scientists detected a circumplanetary disk around exoplanet PDS 70c, which is a Jupiter-like planet orbiting a star about 400 light-years away.

IMAGE: This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, shows wide (left) and close-up (right) views of the moon-forming disc surrounding PDS 70c, a young Jupiter-like planet nearly 400 light-years away. The close-up view shows PDS 70c and its circumplanetary disc centre-front, with the larger circumstellar ring-like disc taking up most of the right-hand side of the image. The star PDS 70 is at the centre of the wide-view image on the left. CREDIT: ALMA (ESO/NAOJ/NRAO)/Benisty et al.

New observations published in The Astrophysical Journal Letters show that there is a potential exomoon forming around an exoplanet. And we have images!

Using the Atacama Large Millimeter/submillimeter Array (ALMA), scientists detected a circumplanetary disk around exoplanet PDS 70c, which is a Jupiter-like planet orbiting a star about 400 light-years away. This disk surrounds the planet, similar to how protoplanetary disks surround a star, and it’s full of dust that could be turned into a moon. An exomoon. And we have managed to get a picture of that disk. What a time to be alive, people.

Here’s what we basically know of planetary formation. The details get murky, so this is simply an upper-level understanding. A star forms and is surrounded by a circumstellar disk full of dust. That dust can then coalesce into planets, which will pull more and more dust and debris into them and grow as they collect material. Not all of the dust ends up in the planet but can turn into a circumplanetary disk of dust that now orbits the planet and could similarly coalesce into a moon or three. Lead author Myriam Benisty commented: Our ALMA observations were obtained at such exquisite…