Why is it in News?
→ Debris struck the Chinese crewed vehicle Shenzhou-20 causing a crack in the return capsule window.
→ Raised concerns regarding astronaut protection from MMOD in Earth’s orbit.
Important Points
- Micrometeoroids size ranges from micrometres to about 2 mm
- Originate mainly from asteroid belt collisions
- Some originate from comets
- Travel at speeds of 11–72 km/s
- Distribution slightly higher near Earth due to gravity
- Cause billions of impacts on spacecraft annually
- Orbital debris consists of non-functional human-made objects
- Originates from exploded rockets, satellites, collisions, ASAT tests
- Average orbital debris speed is about 10 km/s
- Concentrated mainly in Low Earth Orbit (200–2000 km)