The first known interstellar visitor to the solar system, 'Oumuamua, highlights how life could also spread between the stars, and perhaps even across the galaxy, two new studies find.
In 2017, astronomers detected a cigar-shaped asteroid named 'Oumuamua, or A/2017 U1, a chaotically tumbling 1,300-foot-long (400 meters) object whose trajectory suggests it may have come from another star, or perhaps two. Researchers since learned that 'Oumuamua is unlike anything seen in the solar system, varying in color across its surface in a way no scientists could at first explain.
Previous research estimated there were about a million billion interstellar objects comparable in size to 'Oumuamua per 35 cubic light-years, much higher than some prior estimates. This led scientists to explore the implications such astronomical numbers of 'Oumuamua-like bodies might have for the prospect of lithopanspermia — the idea that life might have spread throughout space by hitchhiking on rocks. ['Oumuamua: The Solar System's First Interstellar Visitor in Photos]
"Interstellar objects could potentially plant life from another planetary system in the solar system," Avi Loeb, an astrophysicist at Harvard University and senior author on both of the new studies, told Space.com.
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