Seventy years ago, Earth had only one satellite: the Moon. Now it has more than 15,000 – about 10,000 of which are owned by Elon Musk’s SpaceX. The world’s first trillionaire plans to launch one million more satellites, each roughly 70 metres long and 20 metres wide, that would form a data centre megaconstellation.

But more satellites means more space junk, which is already threatening critical infrastructure we rely on every day.

Addressing this problem effectively requires work across three fronts: technology, policy and philosophy.

The race to the Moon and beyond is accelerating. Some say it’s for the benefit of all humanity. But is it really? In this seven-part series, we explore what our future in space will look like, how we might travel and survive out there, and what’s needed to stop a catastrophe from happening.

13 million cane toads worth of space junk

Space junk is everything in Earth orbit that doesn’t have a purpose. It includes discarded rocket bodies, defunct and broken satellites, and fragments down to nanoparticle size. There are 36,000 pieces of junk larger than ten centimetres and tens of millions of smaller pieces and particles.

The estimated weight of all of this junk is 13,486 tonnes, the equivalent of 13 million adult cane toads. The United States, Russia (as well as the former USSR), and China are the........

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