Asteroid 2024 YR4 No Threat to Earth, but Maybe the Moon

As many scientists expected, further observations of asteroid 2024 YR4 have reduced the chances of it colliding with Earth to basically zero. The asteroid made headlines a month ago when it appeared it had a small chance of impacting our planet in 2032.  However, NASA is not ruling out the possibility it might hit the Moon instead.

Astronomers detected 2024 YR4 on December 27, 2024 using the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile. It rose on NASA’s automated Sentry risk list on December 31 and soon made headlines because it was estimated to have a “non-zero probability” of hitting Earth on December 22, 2032.

It was a very small probability, about one percent, but that was higher than any other asteroid and it’s pretty big, 130-300 feet (40-91 meters) in diameter.  If it did hit, the consequences could be dire.

As observations continued, the risk grew at first and then diminished, a common occurrence in tracking asteroids.

ESA first estimated the risk at 1.2 percent and it rose to 2.8 percent, but quickly dropped to 0.16 percent by February 21.

NASA reached the same conclusion. In a blog post today, the agency reported that “the range of possible locations” where it could be on December 22, 2032 have “moved farther away from Earth.”

But the Moon might still be in its sights. There’s a 1.7 percent chance it will strike there.

Observations will continue.  NASA’s Center for Near Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory keeps track of comets and asteroids — Near Earth Objects (NEOs) — in Earth’s vicinity. The CNEOS automated Sentry website is a good place to keep up to date on 2024 YR4 and other NEOs.