Orbiting the Earth alongside our working satellites is a growing swarm of debris — dead spacecraft, spent rocket stages and countless fragments — hurtling around the planet fast enough to destroy anything they hit. This episode explores space junk, and the unsettling scenario in which it could feed on itself.

You'll come away understanding where orbital debris comes from, why even a fleck of paint is dangerous at orbital speed, what the "Kessler syndrome" is, and what's being done to keep the space around Earth usable.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: ESA – "Space debris" pages; NASA Orbital Debris Program Office; Donald Kessler's 1978 paper (widely summarised online).