Space Junk Fell From Sky and Crashed Onto Cattle Farm

A piece of rocket debris hit the ground on a farm in Australia, making it the fourth in a series of space junk impacts in the region.

The most recent chunk was found by cattle farmer Jordan Hobbs on August 13 while feeding his cows on his farm near Tumbarumba, around 100 miles southwest of the Australian capital city Canberra.

"I thought it was rubbish and I was going to throw it in the bin," he told ABC South East NSW. "We made a bit of a joke that it could have been space junk."

Space junk is the name for pieces of man-made materials in space that are obsolete and therefore are at risk of falling to Earth when their orbit decays. The larger the piece of debris, the larger the number of individual pieces falling back into the atmosphere.

"It is always difficult to assess the amount of surviving mass and number of fragments without knowing the design of the object, but a reasonable "rule-of-thumb" is about 20-40 percent of the original dry mass," Holger Krag, head of the Space Safety Program Office for the European Space Agency, told SpaceNews.

According to Australian National University astrophysicist Brad Tucker, the recent piece of debris that landed near Tumbarumba was small and light, so it wasn't too dangerous.

"This piece was very light, and so it fell pretty slowly to the ground," he told Newsweek. "Then the whole trunk hits the atmosphere, it is traveling 25,000 km/hr [around 15,500 mph]. It loses a lot of energy when it breaks apart, and so the bits that break off, fall to the ground a lot slower. You still would not want to be under it!"

Larger and therefore faster moving pieces of debris may cause significantly more damage and could pose a risk to human life.

"The trick is that you actually want bits to break off, else it will come down as one giant piece. What needs to happen is for these bits to come down controlled, intact, which means they can be controlled where to land and hopefully re-used," he said.

The other three pieces of debris recently found in Australia fell in a relatively straight line across the country, with others being discovered in the Snowy Mountains in early July.

SpaceX confirmed on August 4 that the previous pieces of debris were indeed from its Dragon capsule. However, the company also said that incidents like these were to be expected.

"We did get reports of debris of the Dragon trunk that had landed in the outback of Australia," Benjamin Reed, senior director of the SpaceX Human Spaceflight Program, said in a livestreamed conference at NASA.

"The important news is of course there was no injury or damage. Also importantly is this was all within the expected analyzed space of what can happen."

However, not everyone appreciated the sentiment that space junk falling from the sky should be something to be expected and tolerated.

"I'm not satisfied by that response," Space Law Lecturer at UNSW Canberra Duncan Blake told ABC South East NSW.

"I think it's a bit dismissive and I think that SpaceX ought to be doing more than simply saying that it was within their analysis," he said. "I wonder whether they coordinated with Australia when they made that risk assessment. If they didn't, then that seems somewhat arrogant to make a decision that affects Australia without consulting Australians."

It is thought that SpaceX is also responsible for the fourth piece of debris, although it has yet to confirm these claims.

According to NASA, the chances of any one person being hit by a piece of space debris are around 1 in 3,200, meaning that the risk of a particular person being hit is extremely low.

However, according to research published in the journal Nature Astronomy, the increase in space junk in Earth's orbit has meant that the chances of pieces of debris falling from the sky are increasing.