The chances that Asteroid 2024 YR4, a rock between 130 and 300 feet wide, will crash into the Earth (or, probably, just explode above the planet’s surface) just before Christmas 2032 have been creeping up. When I wrote about this the other day, the odds of an ugly encounter between that rock and ours had risen from 1.6 to 1.9 percent. They have now risen to 2.3 percent. Should the asteroid hit, it would be far from an extinction-level event for humanity, but while that’s good news, an airburst would, it is thought, be equivalent to about five hundred (there are higher or lower estimates) Hiroshimas, very bad news for any city in the neighborhood.

As I mentioned in that earlier post, the International Asteroid Warning Network says YR4’s “impact risk” corridor is “across the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia.”

2032 is still a long way away, and the odds can move down as well as up, but the increase in the still remote chance of a hit underlines the case for starting preparations to act against YR4 the next time it returns to our neighborhood in 2028. A “deflection” mission such as that pulled off by NASA’s DART in 2022 typically takes three to five years to put together, so the case for at least beginning preparations for such an enterprise is now looking even stronger. Even if it proves unnecessary, it would be a useful training exercise, and that seems worthwhile. Sooner or later something nasty will head our way, so we had better be prepared. The DART mission cost $325 million, roughly equivalent to the cost of between 80-125 wind turbines, of, shall we say, questionable value.