Washington, September 14 (ANI): An international team of astronomers has discovered that Jupiter had captured the comet 147P/Kushida-Muramatsu as its temporary moon in the mid-20th century, in an irregular orbit for about twelve years.
There are only a handful of known comets where this phenomenon of temporary satellite capture has occurred and the capture duration in the case of Kushida-Muramatsu, which orbited Jupiter between 1949 and 1961, is the third longest.
The phenomenon was detected by an international team led by Dr. Katsuhito Ohtsuka that modeled the trajectories of 18 "quasi-Hilda comets", objects with the potential to go through a temporary satellite capture by Jupiter that results in them either leaving or joining the "Hilda" group of objects in the asteroid belt.
Most of the cases of temporary capture were flybys, where the comets did not complete a full orbit.
However, Dr. Ohtsuka's team used recent observations tracking Kushida-Muramatsu over nine years to calculate hundreds of possible orbital paths for the comet over the previous century.
In all scenarios, Kushida-Muramatsu completed two full revolutions of Jupiter, making it only the fifth captured orbiter to be identified.
According to Dr. David Asher, "Our results demonstrate some of the routes taken by cometary bodies through interplanetary space that can allow them either to enter or to escape situations where they are in orbit around the planet Jupiter."
Asteroids and comets can sometimes be distorted or fragmented by tidal effects induced by the gravitational field of a capturing planet, or may even impact with the planet.
The most famous victim of both these effects was comet D/1993 F2 (Shoemaker-Levy 9), which was torn apart on passing close to Jupiter and whose fragments then collided with that planet in 1994.
Previous computational studies have shown that Shoemaker-Levy 9 may well have been a quasi-Hilda comet before its capture by Jupiter.
"Fortunately for us Jupiter, as the most massive planet with the greatest gravity, sucks objects towards it more readily than other planets and we expect to observe large impacts there more often than on Earth," said Dr. Asher.
"Comet Kushida-Muramatsu has escaped from the giant planet and will avoid the fate of Shoemaker-Levy 9 for the foreseeable future", he added. (ANI)