In a first, astronomers spotted a space rock turning into a comet
The process won’t be complete until 2063
![comet](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2020/08/081420_lg_comet_feat.jpg?fit=1028%2C579&ssl=1)
Space rocks called centaurs could someday become brilliant comets, like the one shown in this artist’s illustration. Astronomers have spotted a centaur that is expected to become a comet in about four decades.
Heather Roper/Univ. of Arizona