What is space debris?
Space debris is every human-made object in orbit that no longer serves a purpose: dead satellites, spent rocket stages, explosion fragments, even flecks of paint. About 36,000 pieces larger than 10 cm are tracked — alongside an estimated 130 million fragments too small to track, each moving ~10× faster than a bullet.
Where the junk comes from
The worst single events are breakups: the 2007 Fengyun-1C anti-satellite test and the 2009 Iridium-Cosmos collision each created thousands of trackable fragments that still orbit today. Cosmik's Debris filter shows the major clouds — over 2,600 catalogued fragments.
Conjunctions: orbit's near-misses
A 'conjunction' is a predicted close approach between two objects. Operators receive thousands of warnings weekly; the ISS performs avoidance manoeuvres about once a year. Cosmik ingests CelesTrak's SOCRATES predictions and can warn you when a satellite you follow has a close approach.
Kessler syndrome
The nightmare scenario, described by NASA's Donald Kessler in 1978: past a critical density, each collision creates fragments that trigger further collisions — a slow chain reaction that could make some orbits unusable for generations. It is why modern rules require satellites to deorbit within years, not decades.