flash Iridium

EN Texte en anglais Pas encore d'article dans ta langue : extrait en anglais.

Satellite flare, also known as satellite glint, is a brief and bright "flare" in visibility of a satellite. It is caused by the temporary direct reflection of light from the surface of a spacecraft in orbit, such as from its solar panels or antennas (e.g., synthetic aperture radar), toward an observer. As a form of light pollution it can negatively affect ground-based astronomy, stargazing, and indigenous people. Many satellites flare with magnitudes bright enough to see with the unaided eye, i.e. brighter than magnitude +6.5. Smaller magnitude numbers are brighter, so negative magnitudes are brighter than positive magnitudes, i.e. the scale is reverse logarithmic (see apparent magnitude). The Iridium constellation was one of the first anthropogenic sources of near-space light pollution to draw criticism. Larger satellite constellations, like OneWeb and Starlink, have received increased criticism. Scientific and policy analyses have raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight in ways that affect astronomy, stargazers, and indigenous communities.