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Moonlight Kept the Space Stations Visible Through Midnight
A 0.6-meter telescope recorded 147 night detections and a model found lunar Earthshine can boost nadir-facing radiance by at least 100 times over starlight.
Summary
A 0.6-meter telescope recorded 147 night detections and a model found lunar Earthshine can boost nadir-facing radiance by at least 100 times over starlight.
Optical tracking usually depends on sunlit satellite passes near twilight. The authors add moonlight and lunar Earthshine to sunlight and Earthshine in a satellite-brightness model, then compare it with what they describe as the first quantitative night observations of the ISS and Chinese Space Station illuminated only by lunar sources. The 147 ISS detections had median brightness V equals 12.02 plus or minus 0.17, about 13.1 magnitudes fainter than daylight. Their model suggests large spacecraft can remain within reach of modest telescopes for much of the night and up to roughly 11 nights per lunar month at local midnight.
Why it matters
A 0.6-meter telescope recorded 147 night detections and a model found lunar Earthshine can boost nadir-facing radiance by at least 100 times over starlight.
Limits and context
- The authors add moonlight and lunar Earthshine to sunlight and Earthshine in a satellite-brightness model, then compare it with what they describe as the first quantitative night observations of the ISS and Chinese Space Station illuminated only by lunar sources.
- Their model suggests large spacecraft can remain within reach of modest telescopes for much of the night and up to roughly 11 nights per lunar month at local midnight.
Key claims
A 0.6-meter telescope recorded 147 night detections and a model found lunar Earthshine can boost nadir-facing radiance by at least 100 times over starlight.
Qualification: The authors add moonlight and lunar Earthshine to sunlight and Earthshine in a satellite-brightness model, then compare it with what they describe as the first quantitative night observations of the ISS and Chinese Space Station illuminated only by lunar sources.
Evidence: source-2026-09-09-015
Sources
- arXiv preprint 2609.07057arXiv · primary research
Corrections
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