As more space debris crash lands into Earth, how likely are you to be hit by space junk?

In the last two months, there were two separate incidents of space junk cropping up in surprising places, and one of these crash-landed in Australia.

The amount of space debris floating around in our orbit has steadily increased since the beginning of the space age, according to the European Space Agency, and it's set to skyrocket as more is sent up.

Space debris is anything man-made that is re-entering the Earth's atmosphere, said aerospace engineer Fabian Zander, and as more space debris collects above us, we'll likely see more crash-landing on Earth, too.

Mr Zander, who is a senior research fellow at the University of Southern Queensland, said as space debris increases so does the likelihood of it hitting a person or landing in someone's backyard.

So, what really are the chances of being taken out by a chunk of space junk, and should we be doing something about it?

According to Mr Zander, the likelihood of space debris hitting a person is about one in 10,000.

That number seems like a lot, considering the chance of being struck by lightning in Australia is about one in 1.6 million, and the chance of winning the Powerball is less than one in 134 million.

Compared to those odds, one in 10,000 seems pretty likely.

In reality, that estimate is the likelihood that any person would be hit by space junk, but the odds of an individual person taking the hit sits at around one in a trillion, Mr Zander said.

Only one person has ever been hit by space junk, Mr Zander said, Oklahoma woman Lottie Williams, who was knocked on the shoulder by a chunk of rocket in 1998.

In July, we had our very own galactic encounter in NSW's Snowy Mountains, when a fragment of one of Elon Musk's spacecrafts crash-landed in a rural field.

A handful of other SpaceX pieces have since been located around regional NSW.

Mr Zander said the Space X components were from about two years ago when the company first sent people up in a rocket.

"They had a couple of components that they discard that are no longer needed," he said.

"They were actually in orbit for the last two years, in a random, uncontrolled orbit around the Earth, and they came in and landed in outback NSW."

Earlier in the month, suspected space debris from a Chinese rocket crashlanded in Indonesia and Malaysia, Mr Zander said.

When unwanted parts of China's rockets are discarded, they enter an uncontrolled orbit, hurtling around the Earth and high speeds.

"It's anyone's guess where it will actually come in," he said.

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Mr Zander said the Chinese rocket part was the third of its type: the first was a 12-metre component that dropped on an African village, flattening some of the buildings, and the second landed near the Maldives.

As more satellites, rockets and other commercial equipment is launched, space law and regulation must advance to meet advancing innovation, Flinders University space law expert Joel Lisk said.

Mr Lisk said while we regulate launch activity, we don't regulate what happens after the material goes up into space.

The commercial space industry is now starting to ask for laws, Mr Lisk said, as commercial entities need a level of regulation to thrive.

"What we need to do, from our perspective, is to have laws that are modern, flexible and responsive in a way that you don't need to be extremely specific, to still enable innovation," he said.