More than 1 million “interstellar objects” the size of the Statue of Liberty could be drifting unseen in the outer solar system right now, new simulations suggest. The hefty cosmic interlopers, which have traveled here from our closest stellar neighbors, are unlikely to ever come near Earth. However, smaller interstellar particles are likely hitting our planet every year, the study finds.
Until now, scientists have only detected two confirmed interstellar objects in the solar system: the unusually oblong object ‘Oumuamua, which some people incorrectly suspected was an alien probe when it was spotted in 2017, and Comet Borisov, which was discovered in 2019. Both of these objects, which are now long gone, were spotted sailing through our cosmic neighborhood at high speeds, making it clear that they originated from interstellar space.
However, scientists have long suspected that many other alien objects pass through the solar system undetected every year, and that even more interlopers likely reside here permanently. Several spacecraft, including NASA‘s now-deceased Cassini probe, have also previously detected tiny interstellar dust particles streaming through the solar system.