Space is trashed – here's how it could be cleaned up

You're standing in your backyard on a clear night. The air has cooled, the streetlights have dimmed, and the sky has settled into its familiar pattern – a scatter of stars you half remember from childhood. With a bit of patience, you might even pick out the Great Bear.

What you won't see, at least not with the naked eye, are the thousands of human-made objects sharing that same space: dead satellites, spent rocket stages, and fragments from collisions. Earth's orbit is growing crowded. As of late 2024, according to the European Space Agency (ESA)'s latest annual space environment report, nearly 40.000 objects are actively tracked around Earth, more than half of them in Low Earth Orbit (LEO), the region most heavily used for Earth observation. Beyond what can be tracked, models estimate more than a million fragments larger than one centimetre, and tens of millions smaller still, travelling at speeds high enough to disable or destroy operational satellites.