Satellite flare

It is caused by the reflection toward the Earth below of sunlight incident on satellite surfaces such as solar panels and antennas (e.g., synthetic aperture radar).

Streaks from satellite flare are a form of light pollution that can negatively affect ground-based astronomy, stargazing, and indigenous people.

[7][8][9] Scientific and policy analyses have raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight in ways that affect astronomy,[10][11][12] stargazers,[13][14] and indigenous communities.

Occasionally, an antenna reflects sunlight directly down at Earth, creating a predictable and quickly moving illuminated spot on the surface below of about 10 km (6 mi) diameter.

Such flares lasted about twice as long as those from the main mission antennas (MMA), because the so-called "mirror angle" for the solar panels was twice that for the MMAs.

Planned low-orbit satellite constellations such as Starlink are a concern for astronomers, stargazers, and indigenous communities because of light pollution.

[4][21][22][23] In February 2020, the Russian Academy of Sciences said it would send a letter to the United Nations complaining that Starlink's satellites will damage "30-40% of astronomical images.

[36][37][38][39] Starlink satellites can flare repeatedly in an isolated area of the sky, typically directly above the sun (below the horizon) as they transit the highest latitude of their orbits.

[40] The flares from Starlink have been misidentified as UFOs by airline pilots[41][42] due to their unusual repetitive nature, which is visually analogous to a car's headlights at night getting brighter (then dimmer) as it rounds a turn.