A sharp-eyed amateur astronomer found what could be a moon at Jupiter, representing an interesting evolution in astronomy.
Kai Ly found the moon (potentially Jupiter’s 80th) while they were browsing 2003 data from the 3.6-meter Canada-France-Hawaii Telescope. The archive is a rich treasure trove of information because previously, investigators David Jewitt and Scott Sheppard (both of the University of Hawai‘i) used it to find and announce 23 new moons at Jupiter.
“I’m proud to say that this is the first planetary moon discovered by an amateur astronomer,” Ly said in a message on the Minor Planet Mailing List, which goes out to members of the community. The moon is not professionally confirmed yet, but Ly submitted their findings for confirmation to the Minor Planet Electronic Circular, an International Astronomical Union bulletin that publishes such discoveries.
As Ly pointed out, moons tend to be out of reach of amateur astronomers because they do not get access to the professional-class observatories that professional ones do. That said, the world of astronomy rapidly changes as new technology comes to the fore. Computer software allows amateurs to process images to a near-professional degree these days, and as artificial intelligence and machine learning become more common and affordable, it may be that amateurs use such technology for planet- or moon-hunting along with professionals.
There probably are a lot of little worlds still lurking in the outer solar system, but these days we often find them while searching for something else. For example, in 2018 a Carnegie Institution for Science-led team searching for the fabled Planet Nine (a large solar system planet that may lie far beyond the realms of Neptune) found 12 moons around Jupiter, including an unusual moon that orbits in the opposite direction of other moons that are also situated far away from the gas giant. Its orbit crosses that of so many other moons that it also poses a potential collision hazard.
This team was also using professional images from the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile. Data protocols can vary at different telescopes, but in general a discovery team does have an embargo upon the information for at least a little while before it is opened up more broadly. Those telescopes with open archives, however, may present a rich treasure trove for talented amateurs to make their own discoveries, just like Ly did.
So where does this leave the future of amateur astronomy finds? Looking at the history of comets may be a fun comparison. In the latter 20th century, amateurs found a lot of comets because these tend to be better suited to all-sky surveys, while astronomers of the era tended to focus in on a small number of targets. But again, that has changed quickly. We now have a number of all-sky telescopes that can pick up such objects, and “sungrazers” (comets whizzing past the sun) have been found numerous times with a NASA-European Space Agency space telescope that monitors solar weather called the Solar and Heliospheric Observatory. SOHO is 25 years old, but is still operating well.
That said, professionals and amateurs now work together regularly through crowdsourcing projects and other astronomy opportunities that unite the volunteer efforts of amateurs (who may have more time to spare, or a creative approach to bring) to the professionals with access to big telescopes. And sometimes that results in comets, too. For example, an Australian amateur astronomer, Joseph Brimacombe, independently confirmed a comet in 2017 first found in the All Sky Automated Survey for Supernovae (ASAS-SN) in which he was participating.
All told, this means opportunities remain rich for amateurs to make discoveries. Archival data and crowdsourcing projects are just a couple of ways that you can get involved in astronomy, even without a degree or fancy equipment. And as technology improves, opportunities should proliferate even more for enthusiasts of the sky to find even more interesting things in the cosmos.