First Trojan Asteroid Confirmed Around Saturn – Thought to Be “Stolen”

Saturn has joined the ranks of giant solar planets with Trojan asteroids. But all may not be as it seems on face value as it may have “stolen” its trailing follower…

The Curious Case of Trojan Asteroid 2019 UO14

It seems that the Trojan asteroid called 2019 UO14, was taken in by Saturn after it had bounced around the solar system. The orbit of the Trojan is also not stable and it could be that the asteroid leaves its orbit. 

Astronomers are working to find more asteroids that may be within Saturn’s orbit. The discovery team member Paul Wiegert, an astronomer at the University of Western Ontario, explained: “We think it is about 9 miles (15 kilometres) across, though its composition is unknown, it probably originated from the Kuiper Belt beyond Neptune.”

He also went on to say that “The Trojan asteroid was in the process of gravitationally ‘bouncing’ between the giant planets when it got snagged by Saturn.” Trojan asteroids normally sit at an average separation of 60 degrees as seen from the sun’s vantage point and this discovery now means all the gas giant planets are now known to have Trojan asteroids. 

The Trojan Leader

Jupiter is the planet with most Trojan asteroids. In fact, it is a non-contest. The planet has 10,000 of them which have had to be divided into two different categories: the Greek camp and the Trojan camp. The first discovered Trojan around Jupiter was actually identified in 1906, so Saturn could be considered as “lagging behind”. UO14 was first seen in 2019, but it has only now been established that it is within the orbit of the planet.

NASA mission Lucy will visit the Greek camp in August 2027 as it is scheduled to perform a flyby of Eurybates and its moonlet. The craft is due to see three more of the Greek camp asteroids before ending its mission in 2033.

Wiegert, talking to Space.com, explained that the Trojans of Saturn are not actually any more difficult to detect. This raises a question of why they haven’t been discovered earlier. He attributed patience to the discovery:

“We didn’t really do anything different in terms of the approach used in this case; it was really just a matter of carefully watching the lists of nightly small body observations looking for likely candidates,” he said. “Kudos go to Andrew Walker of Australia, one of our co-authors, for noticing it first.”