How worried should we be about asteroids?

You "may want to keep your head down" on 22 December 2032, said Time. That's the day an asteroid may strike our planet.

The chances of 2024 YR4 striking Earth increased this week to 1 in 32 but then dramatically fell to just 1 in 67 after further observations, leaving lots of people confused about just how worried we should be.

What did the commentators say?

2024 YR4 measures only 130 to 300 feet across, "a pebble" compared to the asteroid that "killed the dinosaurs", which is thought to have been six to nine miles in length.

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But it's "moving fast" – about 38,000mph – and it's that "screaming speed" that causes even a relatively small asteroid to "pack such destructive force" because the energy is "dissipated when it collides with something like a planet".

Humanity "does not have to be a passive target", though, because Nasa could use a kinetic impactor mission similar to DART in 2022, which "succeeded wildly" when it successfully nudged a different asteroid and changed its orbit.

"It's far from panic stations" for Earth, said Sky News. This is partly because the asteroid is "made of a rocky substance", which means it could "break into smaller pieces if it enters Earth's atmosphere".

So "I'm not worried just yet", said Carrie Nugent, author of "Asteroid Hunters", in The Guardian, because "we’ve got time to prepare" and the asteroid is "not terribly large by asteroid standards".

Also, the surface of the Earth is "mostly water" and "most experts would agree" that a 40- to 90-metre asteroid-ocean impact could happen "without loss to human life or property".

Studies suggest that the "risk corridor" of expected impact covers the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea and South Asia, said Forbes.

But it's not just Earth that's under threat: current calculations from Nasa estimate a 0.8% impact probability – so, a 1-in-125 chance – that the asteroid will "hit the moon rather than Earth".

What next?

The asteroid is expected to disappear from view around April, so further observations are being "conducted in a hurry", said The Independent. It will not be possible to study it again until 2028 – "at which point it could be too late".

The James Webb Space Telescope, which has an infrared eye that allows it to track the asteroid further out than optical light telescopes, will improve our understanding of the asteroid, Robin George Andrews, author of "How to Kill an Asteroid", told Ars Technica. Its "first observations" should appear by the end of March.

Meanwhile, it's important that countries work together on the threat of asteroids because global cooperation is, "unsurprisingly for a threat that comes from the stars", absolutely "essential", said The Washington Post.