Killer Asteroid Will Miss Earth But Return for a Shot at Revenge

Remember the potential "city killer" asteroid we were all freaking out about, 2024 YR4? Initially predicted with a small but unsettling chance of hitting our planet seven years from now, astronomers eventually ruled out that apocalyptic outcome once they were able to get better observations. But the saga's not over. 2024 YR4 will be back for another pass, Athabasca University astronomer Martin Connors writes in an essay for The Conversation — and there'll be others like it. As Connors explains, YR4 exhibits what's known as "orbital resonance" with Jupiter, meaning that it moves at a multiple of the speed of the gas giant. While Jupiter takes roughly 12 years to orbit the Sun, asteroids like YR4 only take four, putting it in a 3:1 resonance. The upshot, in an "Armageddon" context, is that resonant asteroids close enough to cross Earth's orbit will have multiple attempts to hit the bullseye. "Among asteroids, we must pay special attention to resonant ones, such as 2024 YR4, because e ... Read full article.