Near miss just in time for Asteroid Day

Asteroid 2024MK is expected to be closest to Earth on June 29.

2024MK is a relatively large asteroid given how close it will pass by Earth but University of Southern Queensland astrophysicist Jonti Horner said it was nothing to lose sleep over.

"There's things flying past all the time, but compared to the size of the space around us, the Earth is a vanishingly small target," Mr Horner said.

The asteroid, which is about 150 metres wide, will be passing Earth at about 80 per cent of the distance between us and the moon.

"Now the moon is 380,000 kilometres away, which means that this is missing us by 300,000 kilometres," Mr Horner said.

"So that's the equivalent of me living in Toowoomba panicking because there's a car in Perth that's driving vaguely in my direction."

The asteroid is passing by just in time for Asteroid Day on June 30, an internationally recognised day, which aims to raise awareness of the risks of asteroid impact.

"We're in this bizarre situation where we are the first generation of life on our planet to actually be able to find things before they hit us and predict when they'll hit us," Mr Horner said.

"When you've got a species that can see things coming in, realise they're going to hit us, predict where they'll hit us and see the results, and it's only a very small step from that to be able to see them coming in and do something about it."

Scientists have accurately predicted a handful of space objects heading towards the planet in recent history but all were small enough that they exploded in the Earth's atmosphere.

Diverting an asteroid large enough to make it through the atmosphere was still somewhat in the realm of science fiction but there were plans in place.

In 2021, NASA's Double Asteroid Redirection Test experimented with sending a spacecraft into an asteroid to test how it might be deflected.

"If we had enough prior warning, there are things we can do," said Mr Horner.

"But to do that, we need to find them, and to be able to do that, we need to protect our ability to see these things on the way in."

Mr Horner said the sky around Earth risked becoming cluttered with satellite constellations.

"It's giving people fabulous access to the internet where they couldn't get it otherwise but it's also creating a kind of sleet of objects in the foreground that make it harder to see the things," he said.

"We need to preserve our ability to see the night sky because of all the joy and the wonder it brings, but also so that we can address this potential threat and we need to do things in a balanced and a thought-out way."

Asteroids are visible to the naked eye if they come about 10 times closer than 2024MK is predicted to.

Avid star-gazers are likely to miss it without access to a big telescope.

"Maybe a big backyard telescope if you knew where to look, but it would just look like a single point of light moving against the background stars," Mr Horner said.