Disappointment for research: Asteroid 2024 YR₄ will clearly miss the Moon

The near-Earth asteroid 2024 YR₄ will also miss the Moon shortly before Christmas 2032, thus posing no danger to Earth even via this detour. This has been revealed by two observations with the James Webb Space Telescope, which became possible much earlier than expected in February, the European Space Agency ESA has now announced. It was originally stated that the celestial body could only be observed again in several years and certainty about its orbit could be obtained in 2032. However, in February, there was an unexpected opportunity to determine its orbit more precisely. The measurements have accordingly shown that the asteroid will miss the Moon by more than 20,000 km.

Impact could not be ruled out for an unusually long time

As the ESA explains, in February 2024 YR₄ flew past stars from the perspective of the most modern space telescope, the position of which was known very precisely thanks to the Gaia space telescope. Despite the data, it was an enormous challenge to find one of the faintest asteroids again. This was achieved with the Near-Infrared Camera (NIRCam). “Decades of engineering work, international cooperation and innovations in science, technology and planetary defense culminated in the use of humanity's most powerful robotically controlled space telescope, built by many nations, to discover a distant speck of dust in the void and answer a question of universal importance to all inhabitants of our planet,” the ESA now summarizes.

2024 YR₄ caused a stir for weeks at the beginning of 2025 after the asteroid was discovered on December 27, 2024, shortly after its most recent rendezvous with Earth. Subsequent observations then revealed that an impact of the asteroid on its next-but-one rendezvous with our home planet could not be ruled out. For several weeks, and thus an unusually long time, the asteroid was therefore at the top of the ESA and NASA lists of the currently most dangerous celestial bodies. Only a year ago, the observation data revealed that no danger threatened Earth from the approximately 60-meter-large celestial body.

After a danger to Earth could be ruled out, the focus shifted to the fact that the asteroid could still hit the Moon. Even then, it was considered significantly more likely that both objects would miss each other. However, since the asteroid could no longer be observed with our instruments for now, the determined probability of a collision was 4.3 percent. In research, despite this very low probability, fingers were kept crossed diligently, because such an impact with such a long lead time would have been a unique opportunity for science. Now it is clear that this will not happen.

(mho)