They have planets, the earth has one and even smaller celestial bodies cast a spell on them: we’re talking about moons. However, smaller chunks only rarely move around asteroids. Astronomers have now observed this case in a Trojan, an asteroid that moves in the orbit of the planet Jupiter. According to a NASA press release, the Trojan horse Polymele is being orbited by a natural satellite. This was the result of the analysis of a star occultation campaign organized by NASA’s Lucy mission team.
Polymele measures approximately 27 kilometers in diameter. Their newly discovered moon is about five kilometers wide and orbits the Trojan at a distance of about 200 kilometers. The asteroid is trotting around the sun with Jupiter at a great distance from Earth – about 770 million kilometers the average distance from us.
To get a closer look at Polymele, research teams and amateur astronomers watched the Trojan during a special moment: it passed in front of a star. During the star passage, it was noticed that Polymele is not traveling alone, but is being accompanied by a satellite. According to NASA, the moon has yet to be given a name. To do this, astronomers must first determine the exact orbit of the Trojan satellite, which is expected to be possible in 2027 when the Lucy Polymele spacecraft comes close.
Lucy launched into space on October 16, 2021. The goal of the NASA mission is to explore some Trojans of the planet Jupiter. At the moment, more than 10,500 Trojans are known to be either ahead of or behind Jupiter. The asteroids represent remnants from the early days of the solar system. It is hoped that they will provide clues to the formation of our planetary system. The Lucy mission is expected to last at least twelve years. The spacecraft is planned to visit six Jupiter Trojans and one main belt asteroid between Mars and Jupiter.