As anyone who has ever tried to clean a home knows, ridding yourself of dust is a Sisyphean effort. No surface stays free of it for long. It turns out that space is somewhat similar. Space is filled with interplanetary dust, which the Earth constantly collects as it plods around the sun – in orbit, in the atmosphere, and if it’s large enough, on the ground as micrometeorites.

This article was originally published on 19 April 2021.

Asteroids can pose a threat to life on Earth but are also a valuable source of resources to make fuel or water to aid deep space exploration. Devoid of geological and atmospheric processes, these space rocks provide a window onto the evolution of the solar system. But to really understand their secrets, scientists must know what’s inside them.

There are a lot of things that pose a threat to our planet – climate change, natural disasters, and solar flares, for example. But one threat in particular often captures public imagination, finding itself popularised in books and films and regularly generating alarming headlines: asteroids.

Asteroids — the bits and pieces left over from the formation of the inner planets — are a source of great curiosity for those keen to learn about the building blocks of our solar system, and to probe the chemistry of life.