[modeless]

SpaceX moved the satellites to lower orbits, so any broken satellites or debris will fall out of the sky within a few years due to atmospheric drag. And they are specifically designed to burn up completely in reentry. The real concern is in higher orbits where debris would persist for millennia. This is not a concern for Starlink.

[thekyle]

That's good to hear.

[CrLf]

A collision can eject debris into higher orbits.

[modeless]

Not really. The only way a collision could truly raise an orbit is if a resulting piece of debris had far higher velocity than either incoming satellite which, while maybe not theoretically impossible, seems exceedingly unlikely. Furthermore, the way orbital mechanics works, all orbits resulting from a collision go through the point of the collision, so the collision of two objects in circular orbits can never result in an orbit with higher perigee. The orbit of debris may turn from circular to elliptical with a higher apogee, but those orbits will almost certainly have lower perigees and decay faster.

[NikolaeVarius]

I don't think you understand the magnitudes of distance and energy that we're talking about here