How to Read a Gabbard Diagram
A Gabbard diagram turns each orbit into two dots, so a whole debris cloud fits on one chart.
- Across: the orbital period, the minutes an object takes to circle Earth once. Higher orbits take longer.
- Up: height above Earth. Each object appears twice, at its highest point and at its lowest point.
- The dashed line: circular orbits, where both points sit at the same height. Working satellites cluster on or near it.
- An X: a break-up. Its pieces scatter into faster, lower orbits and slower, higher ones.
- A drift down and to the left: air drag shrinking the orbits until the pieces fall back.
The Break-ups That Shaped Low Orbit
Four events account for thousands of the pieces on the chart. Each card shows the most pieces our snapshots caught in orbit at once, and how many are left. Press a card's button to watch it happen.
Fengyun-1C anti-satellite test
11 January 2007, about 865 km
China destroyed its own retired weather satellite with a missile. Drag is weak at that height, so most of the cloud is still in orbit.
- Most at once
- 2,653 April 2013
- In orbit now
- 1,932
Iridium 33 and Cosmos 2251 collide
10 February 2009, about 790 km
The first accidental collision between two intact satellites: a working Iridium and a dead Cosmos.
- Most at once
- 1,710 April 2012
- In orbit now
- 679
Kosmos 1408 anti-satellite test
15 November 2021, about 480 km
Russia destroyed one of its own dead satellites, and the space station crew sheltered in their spacecraft. Lower down, drag cleared the cloud within a few years.
- Most at once
- 1,094 April 2022
- In orbit now
- 3
Long March 6A upper stages
12 November 2022 and 6 August 2024, near 800 km
Two Chinese upper stages broke apart soon after launch, the second after carrying the first Qianfan satellites.
- Most at once
- 1,305 January 2025
- In orbit now
- 1,182