A few weeks ago, the world looked up to the sky in fear that the asteroid named 2024 YR4 would impact Earth in 2032. Later on, that possibility was ruled out, but the YR4 is back in the news as, according to new data from the James Webb Space Telescope, the asteroid now has almost a 4% chance of colliding with the Moon, as reported by Afp.
It is estimated that the asteroid, about 60 meters in size and capable of destroying a city, set a new record in February with the highest probability ever measured by scientists - 3.1% - of impacting Earth. Subsequent observations eventually ruled out the asteroid impacting Earth on December 22, 2032.
However, the chances of it crashing into the lunar satellite have been steadily increasing.
After the Webb telescope focused its powerful gaze on the asteroid last month, the probability of an impact on the Moon is now 3.8%, said NASA.
"There is still a 96.2% chance that the asteroid will not impact the Moon," NASA stated in a release on Thursday.
Richard Moissl, director of the European Space Agency's planetary defense office, said this aligned with their internal estimates of around 4%.
The new Webb data also shed light on the size of the space rock, previously estimated to be between 40 and 90 meters.
It is now believed to measure between 53 and 67 meters, roughly the height of a 15-story building. This is significant because it surpasses the 50-meter threshold required to trigger planetary defense plans.
If the asteroid still had more than a 1% chance of impacting Earth, "preparations for one or more missions to deflect it would already be starting right now," Moissl said.
There are various ideas on how Earth could defend against asteroids on a collision course, including nuclear weapons and lasers. But only one has been tested on a real asteroid.
In 2022, NASA's DART mission successfully altered the trajectory of a harmless asteroid by crashing a spacecraft into it.
"The possibility of observing a significant impact on the Moon is indeed an interesting scenario from a scientific standpoint," Moissl said.
The event would provide a variety of information that would be "valuable for planetary defense purposes", he added.
Mark Burchell, a space scientist at the University of Kent in the UK, told New Scientist that a lunar impact would be "a great experiment and a perfect opportunity."
And on Earth, "telescopes would certainly see it, I would say, and even binoculars could observe it," he added.
"Hopefully, it will be a lunar impact," said Alan Fitzsimmons from Queen's University Belfast in the UK, as reported by New Scientist.
"It would have no effect on Earth, but it would allow us to study for the first time the formation of a lunar crater caused by a known asteroid," he explained.
The asteroid 2024 YR4 is the smallest object ever observed by the Webb telescope, which will provide experts with new data next month to calculate the probability of impact.