NEW ORLEANS — There’s a few 4 % probability {that a} building-sized asteroid will hit the moon in 2032. Furthermore, there’s a few 1 % probability that the asteroid, dubbed 2024 YR4, is not going to solely strike the moon but additionally scatter a mess of tiny meteorites into near-Earth area, probably harming satellites and astronauts.
“This might pose a variety of dangers to Earth-orbiting belongings,” mentioned NASA aerospace engineer Brent Barbee on December 17 on the American Geophysical Union’s annual assembly.
Ought to YR4 hit the moon, the affect might launch as a lot vitality because the detonation of roughly 6 million metric tons of TNT, or about 400 occasions the vitality launched by the Hiroshima bomb.
Shortly after detecting YR4 in December 2024, scientists reported that it might hit Earth. The chances peaked at 3.1 % on February 18; extra observations precluded that collision. Since then, the percentages of a lunar affect have risen, if solely barely.
If YR4 hit the moon, there’s an 86 % probability it could achieve this on the facet going through Earth. If it did, the affect would generate a flash that “ought to most likely be seen [from Earth] relying on the native viewing circumstances,” mentioned astronomer Patrick King, who simulated the affect’s brightness and introduced his outcomes on the assembly.
Based mostly on the estimated collision date of December 22, 2032, Hawaii would have a wonderful vantage level, whereas views from the western United States can be “pretty favorable,” mentioned King, of the Johns Hopkins College Utilized Physics Laboratory in Laurel, Md.
Scientists don’t know YR4’s dimension and mass exactly sufficient to soundly deflect it, Barbee mentioned, although they estimate it’s roughly 60 meters large. What appears extra sensible is to deliberately break up YR4 utilizing a fast-moving impactor or a nuclear blast, Barbee mentioned. This must be achieved at the very least three months earlier than a lunar affect so the ensuing particles spreads removed from Earth, he famous. Ideally, he added, we might ship a reconnaissance mission within the subsequent few years, too.
“If there are any missions to YR4, they might basically want to begin their improvement very, very quickly,” mentioned Barbee, of NASA’s Goddard Area Flight Heart in Greenbelt, Md.
NASA’s James Webb Area Telescope would possibly observe the asteroid in February 2026, which might assist rule out a lunar affect or elevate the percentages to as excessive as 30 %. But when JWST can’t observe the asteroid for any motive, Barbee mentioned, “we could also be confronted with the necessity to make some choices about YR4 within the face of great uncertainties.”

