Overview
- Researchers identified a repeatable cutoff near 67% to 70% of a solar cycle’s peak when low‑Earth‑orbit objects start losing altitude much faster.
- The peer‑reviewed study in Frontiers in Astronomy and Space Sciences tracked 17 debris pieces over 36 years across three solar cycles using sunspot and solar EUV data.
- The mechanism is thermospheric heating and expansion during heightened sunspot activity, which raises air density at orbital heights and increases drag.
- The authors say active satellites feel the same effect, so operators should expect more orbit corrections and higher fuel use near solar maxima.
- The team notes the threshold relates to how close the Sun is to its peak and varied by cycle intensity, and the small sample means broader confirmation is still needed.