Astronomers prepare for one of the largest asteroid collisions in human history

The universe is infinite, which on the one hand is fascinating, but on the other hand it kind of scares me in a way. Almost every week I read about some astronomical event on the internet. Some of them are pleasant: solar eclipses, shooting stars, phenomena that are interesting to look at. But then there are also threats. Asteroid 2024 YR4 has been talked about since early 2025. At that time, there was a three per cent chance that this body would hit our planet. This is no longer the case, but there is now talk that an asteroid is likely to hit the Moon in a few years’ time.

It was already clear last February that a collision with the Earth was not imminent. However, this does not mean that asteroid 2024 YR4 is safe. In December 2032, a body may hit the Moon. The chances are not that high, after analysing data from the James Webb Telescope, experts found that the probability of impact is 4.3%. What would it mean if it did happen?

The Earth is safe

Astronomers are now assuring that for at least the next 100 years, the Earth is safe and is not in danger of colliding with any body. While this is reassuring, it is still not clear what will happen in the case of the Moon. Experts are now monitoring the situation closely and should have a clear picture by 2028 as to whether a lunar threat is real.

An asteroid with a diameter of 60 metres would cause a crater approximately 1,200 metres in diameter when it hits the Moon. “Most of the material from the crater would fall back to the Moon, but a small fraction, about 0.02% to 0.2%, could be ejected at a high enough velocity to leave the Moon,” the experts warn, adding that it is unclear how much this would affect other bodies in space. So this information is not reassuring for my part. Although the percentage numbers are minimal, the bodies would be large enough in real life to do a lot of damage.

Meteorite collectors might be pleased

If an asteroid were to hit the Moon, a flash of light about the brightness of Jupiter would be visible from Earth. However, due to the position of the planets, this flash would not be visible from central Europe. Around 10 000 tonnes of lunar rock would probably have been ejected from the crater, flying at a speed of about 2.4 kilometres per second , according to calculations by a team led by Yifan Heme of Tsinghua University in Beijing.

This could result in many smaller meteorites hitting the Earth. Meteorite collectors would be delighted, but satellite and space station operators would probably not share their enthusiasm. So, although Earth is safe from an asteroid, even if it hits the Moon, it could have some effect (even a negative one) on us. Therefore, from my point of view, it is also a very fascinating phenomenon, but also a bit scary.