Space junk reenters atmosphere faster as sunspot activity peaks

New research links higher sunspot activity in the 11-year solar cycle to faster orbital decay for objects in low Earth orbit.

Solar heating expands the upper atmosphere, boosting drag in the thermosphere and making debris and satellites lose altitude more quickly.

That can shorten debris lifetimes, but it also complicates short-term collision-risk forecasts as objects pass through crowded orbital regions.

The findings matter for debris-tracking models used by NASA, ESA, and operators such as SpaceX, OneWeb, and Project Kuiper.