A group of astronomers has found an explanation for the unusually high speed of a comet that is leaving the Solar System forever. They concluded that it was accelerated by Saturn’s gravity.
The comet under discussion was found by the telescopes of the automated system ATLAS on July 14, 2024. It received the designation A117uUD. Over the next month, astronomers made 145 observations of the object, giving them a pretty good idea of its trajectory.
Analysis of the data showed that the comet moved along a hyperbolic trajectory. Meaning that it developed a third space velocity, enough to leave the Solar System forever and go into interstellar space.
The research team tried to find an answer to the question of what caused the unusually high speed of A117uUD. The most intriguing suggestion was that it was originally an interstellar comet passing through the Solar System, like the mysterious object Oumuamua or Comet Borisov.
But calculations have shown that another scenario is more likely. In January 2022, the comet experienced a very close encounter with Saturn. On the one hand, this makes it difficult to reconstruct its orbit before the encounter. On the other hand, gives an explanation for the high speed. Most likely, the gas giant’s gravity accelerated A117uUD so much that it sent it on an interstellar journey.
Before that, astronomers knew of only one case where the gravity of a giant planet ejected a tailed guest from the Solar System. This happened in 1980 with comet C/1980 E1 after its encounter with Jupiter. According to the researchers, the fact that we have witnessed two such incidents in less than 45 years suggests that the ejection of comets from the Solar System is a fairly regular event.
According to iflscience
