Low Earth orbit is a thin shell of wreckage moving faster than any bullet. Almost all of it is too small to track, and according to ESA it would keep multiplying even if nobody launched anything again.
1.2 millionpieces bigger than 1 cm
That is ESA's estimate of debris larger than a fingernail circling Earth, and each piece is big enough to disable a satellite. Radar networks follow only about 40,000 objects. Everything else is invisible until it hits something.
ESA Space Environment Report 2025 · modelled estimate
01 · The spectrum
Most of it is invisible
Each step down in size multiplies the count, and radar only sees the top sliver of the population.
Log scale: each tick is ten times the one before. Only "tracked" and "active" are counted; the three size classes come from ESA's statistical model.
≈ 1 cm
Can disable an instrument or a critical flight system
> 10 cm
Can shatter a satellite, creating thousands of new fragments
≈ 1 in 30: for every object radar can follow, there are roughly 30 pieces big enough to disable a satellite (40,000 vs. 1.2 million). derived ratio
02 · The swerves
One fleet, 148,696 dodges in six months
Starlink's required reports to the FCC show its collision-avoidance manoeuvres up almost six-fold in two and a half years.
Each point covers a six-month reporting period ending May 31 or Nov 30. SpaceX moves a satellite when collision odds reach 1 in 1 million, a stricter trigger than the 1-in-10,000 industry norm, so part of the rise is policy and not only crowding.
03 · The breakups
Two of the three worst were on purpose
Ranked by catalogued fragments, the worst breakups in history include two deliberate anti-satellite missile tests.
Deliberate (ASAT test)Accidental
Catalogued fragments per event as of 31 Jan 2023. Cosmos 2251 and Iridium 33 were the same 2009 collision, counted separately for each satellite.
04 · The stakes
A system that feeds itself
ESA says that even with zero new launches, debris would keep growing, because breakups now add fragments faster than the atmosphere drags them down.
3+ /day
intact satellites or rocket bodies falling back to Earth
ESA 2025
3,000+
tracked objects added by breakups in 2024 alone
ESA 2025
~32
times the ISS has fired thrusters to dodge debris, 1999–2022
NASA 2022
7.8 km/s
typical speed in low orbit, about 28,000 km/h
Orbital mechanics
05 · The good news
The rules are starting to bite
Most rocket stages in low orbit now get out of the way afterwards.
Rocket bodies in LEO meeting the 25-year de-orbit rule
~90%
…that would also meet the new, stricter 5-year rule
~80%
19 countries and 150+ organisations have signed ESA's Zero Debris Charter, which aims to stop creating new debris by 2030.
ESA Space Environment Report 2025
06 · Why it matters
What you can do
GPS timing, weather forecasts, card payments and disaster mapping all run through this shell of orbits.
Know what's up there
Navigation, forecasts and banking all depend on satellites. Low orbit is shared infrastructure, like the air or the oceans.
Back the clean-up rules
Support the 5-year de-orbit standard, the Zero Debris Charter, and funding for active debris removal.
Oppose missile tests in orbit
One destructive ASAT test made more trackable debris than any other event in history. Ask your representatives to support a ban.