Nasa’s James Webb Space Telescope has confirmed that asteroid 2024 YR4 poses no threat to the Moon, putting to rest months of planetary anxiety.
Webb’s latest observations, taken in late February 2026, have conclusively ruled out any chance of the asteroid striking the Moon in 2032.
Earlier, scientists had already confirmed it would miss Earth. Now, with the Moon cleared too, astronauts, satellite operators, and the rest of us can breathe easily.
The asteroid, first spotted in late 2024, had briefly caused alarm after calculations suggested a small but non-zero chance it could collide with the Moon. That probability has now been reduced to zero.
HOW DID WEBB SPOT SOMETHING SO FAINT?
This is where things get remarkable. At the time of observation, asteroid 2024 YR4 was reflecting as much light as an almond held at the distance between the Moon and Earth. It glowed at a magnitude of about 30, roughly four billion times fainter than the dimmest star a human eye can see.
No ground-based telescope or other space observatory could have spotted it. Only Webb, with its extraordinary sensitivity and precise moving-target tracking, was up to the task.
WHAT DOES THIS FEAT TELL US ABOUT WEBB?
When scientists first discovered asteroid 2024 YR4 in late 2024, they tracked it until May 2025. That was their original observation window.
Then Webb observed it again in late February 2026. So, instead of tracking data ending in May 2025, they stretched their observation to February 2026.
Think of it like this: if you watch a cricket ball leave the bat for just one second, you can make a rough guess where it will land. But if you watch it for two seconds, your prediction becomes far more accurate.
The same principle applies here. The longer you track an asteroid, the more confidently you can calculate where it will be years from now. That is why this extra nine months of observation data made such a big difference in predicting where 2024 YR4 will be in 2032.
More importantly, this exercise proved that Webb can be used as a planetary defence tool for future threats, well before they come close enough for ground telescopes to detect.
Nasa’s upcoming Nancy Grace Roman Space Telescope and the Near-Earth Object Surveyor mission will further strengthen humanity’s ability to track dangerous space rocks before they become a crisis.
The universe just became a slightly safer place.
