The DART mission (Double Asteroid Redirection Test) just successfully slammed into Dimorphos, which is the moonlet of the asteroid Didymos (also affectionately called Didymoon). Over the next few days astronomers around the world will observe Didymos and Dimorphos to see if there has been a change in orbit from the latter. This is humanity’s first real attempt at altering the course of a “killer” asteroid, even if this one isn’t hazardous to us.