A year ago, astronomers spotted something no one had ever seen before: an object visiting our solar system from somewhere else in the galaxy. The object, dubbed ‘Oumuamua, is long since gone, heading rapidly out of our solar system just as quickly as it came. But now that we know interstellar asteroids exist, scientists have been on the hunt for more. And according to a new study by Harvard researchers, there may be plenty to find.
The new study, published on the ArXiv and awaiting peer review, claims the discovery of an additional four interstellar asteroids, with the possibility of discovering hundreds more in the future.
First, the astronomers wanted to determine what an interstellar asteroid in our solar system would even look like. They developed a simulation of what would happen if a rogue asteroid happened to drift too close to our solar system. They found that the Sun and Jupiter have a complex interaction that tends to trap interstellar asteroids in the solar system. The natural next step was to try and find some of those asteroids in real life.
To discover these cosmic interlopers, the Harvard researchers turned to a database of asteroids, comets, and other small solar system objects maintained by the International Astronomical Union. They combed that database for any objects with similar orbits as the ones produced by their simulation. With that filter, they successfully found four possible candidates.
These four candidates—2018 TL6, 2017 SV13, 2011 SP25, and 2017 RR2—might be the first discovered permanent immigrants to our solar system. ‘Oumuamua was just a temporary guest, gone almost as soon as it got here. But these four will stick around for billions of years, giving us a chance to study and explore them in detail.
What’s more, these four might be the first of hundreds of similar asteroids discovered over the next few years. The researchers suggest that the upcoming Large Synoptic Survey Telescope, due to start operations in 2022, will be able to spot much smaller asteroids, dramatically increasing our knowledge of both native and interstellar objects in our solar system.