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. See the live count of tracked debris objects.
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.
Frequently asked questions
How much space debris is there?
Roughly 40,000+ tracked objects larger than 10 cm, around a million from 1-10 cm, and 100+ million smaller fragments — all moving at orbital speed, where even a paint fleck hits like a bullet.
What is Kessler syndrome?
The feared chain reaction where one collision creates debris that causes more collisions, cascading until parts of low orbit become unusable. It's why satellites now maneuver around each other and rules require end-of-life disposal.
Can we clean up space debris?
Prototypes exist — capture nets, harpoons, drag sails, robotic arms — but nothing at scale yet. For now the strategy is prevention: deorbit rules, collision avoidance and tracking. Cosmik shows the tracked debris fields live.
Keep exploring
See it yourself tonight
Theory is better with a sky. Get the next ISS pass times over New York, London, Paris, Tokyo, Berlin or Sydney — or any of 550+ cities. Aurora hunter? Check tonight's forecast for your city.
