Earth has been bombarded by space rocks throughout its history, but we’re lucky no large ones have slammed into the planet lately. Astronomers keep a careful watch on the skies, hoping to spot potential impactors far enough in advance that we can do something about it, and one of the most worrying objects is 99942 Apophis. This skyscraper-sized asteroid might still hit Earth in 2068, according to a new analysis from the University of Hawaii and NASA’s Jet Propulsion Laboratory.
Scientists discovered Apophis in 2004, sounding the alarm when initial observations suggested it had a worryingly high 2.4 percent chance of hitting Earth in 2029. Thankfully, further study lowered that probability to zero. Still, astronomers have been keeping an eye on Apophis ever since — it’s currently considered the third-highest impact threat to Earth, behind 101955 Bennu and 29075 (1950 DA). However, the highest impact risks for those objects are centuries out.