Astronomers have detected the first known foreign object to visit our solar system: a fast-moving comet or asteroid that zipped by our sun last month. Its velocity may send it back out into interstellar space.
Professor Alan Fitzsimmons from the School of Mathematics and Physics at Queen’s University, has been collaborating with colleagues in the UK, USA and Chile to track the object using powerful telescopes like Pan-STARRS 1 in Hawaii.
He said that, upon confirmation that this object is a likely visitor from another star system, “We immediately started studying it [Wednesday] night with the William Herschel Telescope in the Canary Islands, then on Thursday night with the Very Large Telescope in Chile.”
The research team believes that the foreign icy or rocky object may have been the victim of a cosmic billiards game that would be consistent with current theories of early solar system formation. Planets the size of Jupiter and Saturn have a high enough gravity to affect the orbits of nearby objects. In fact, some theorists believe that the large planets in our solar system may have “wandered” and kicked planet-sized objects into the sun or out of our solar system altogether before settling into their current orbits millions or billions of years ago. The object may have been thrown out of its native star system by a gravitational slingshot effect and could have drifted throughout the galaxy as an orphan for millions or billions of years before reaching our solar system.
More observation is needed to determine the properties of this visiting object. Researchers will be able to make more detailed observations as the object’s path brings it closer to Earth. (It probably won’t actually hit Earth.) Scientists have suspected that foreign objects from other star systems can and sometimes do visit our solar system, but this comet or asteroid is the first confirmation that they actually have of this phenomenon.