An artist’s rendering of Oumuamua, a 1,000-foot-long, cigar-shaped object that traveled through our solar system in 2017.Credit…JPL/NASA

Moreover, it was a primordial leftover, originating not from another planetary or star system at all but from a place and time where stars and planets didn’t exist yet: the deep, dark core of an interstellar cloud, one of the galumphing assemblages of gas and dust that shadow the starry lanes of the Milky Way, and where stars are sometimes born.

— Dennis Overbye