By most estimates, our galaxy is a bustling place. Given its hundreds of billions of stars—each accompanied by whirling planets, asteroids, comets, and more—one would expect objects to occasionally be flung into interstellar space. The first of them was found in 2017: officially called 1I/2017 U1 but better known as ‘Oumuamua, it was discovered by chance as it swooped past our sun on an outbound trajectory that rapidly took it beyond the reach of Earth’s best telescopes. Now astronomers think they have found another outcast wandering the space between the stars. But this time, it may linger slightly longer, offering unprecedented scientific opportunities.