‘Oumuamua might be a shard of a broken planet
The solar system’s first recorded interstellar visitor has a new proposed origin story. The enigmatic celestial object known as ‘Oumuamua might be a shard of a planet ripped apart by its star’s gravity, researchers suggest April 13 in Nature Astronomy. Ever since ‘Oumuamua showed up in our solar system in 2017, astronomers have struggled to explain its origin, suggesting that it might be a wayward asteroid, a comet or even an alien spacecraft (SN: 2/27/19). Searching for other explanations, astronomers Yun Zhang at Côte d’Azur Observatory in Nice, France and Douglas Lin at the University of California, Santa Cruz developed computer simulations in which planetary bodies got too close to their parent stars. In these simulations, objects ranging in size from comets to rocky planets orbit relatively lightweight stars. The scientists found that if these bodies repeatedly come within about 600,000 kilometers of their star — nearly 80 times as close as Mercury gets to our sun — then the star’s gravity shreds...