Satellite flare

  • Top: a simulated animation of a typical Iridium flare
  • Bottom: Both images show a flare of an Iridium satellite. Comet Holmes can be seen in the right image, slightly above the tree branch.

Satellite flare, also known as satellite glint, is a satellite pass visible to the naked eye as a brief, bright "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.[1][2][3][4]

Many satellites flare with magnitudes bright enough to see with the unaided eye, i.e. brighter than magnitude +6.5.[5][6] 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.[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.[4][3][15]

  1. ^ "SATCON1 Report". 25 August 2020. Archived from the original on 29 November 2020.
  2. ^ "Media advisory: Press Conference to Unveil Conclusions from Satellite Constellations 1 (SATCON1) Workshop" (Press release). 21 August 2020. Archived from the original on 29 November 2020.
  3. ^ a b Gallozzi, Stefano; Scardia, Marco; Maris, Michele (4 February 2020). "Concerns about ground based astronomical observations: A step to Safeguard the Astronomical Sky". arXiv:2001.10952 [astro-ph.IM].
  4. ^ a b Venkatesan, Aparna; Lowenthal, James; Prem, Parvathy; Vidaurri, Monica (2020). "The impact of satellite constellations on space as an ancestral global commons". Nature Astronomy. 4 (11): 1043–1048. Bibcode:2020NatAs...4.1043V. doi:10.1038/s41550-020-01238-3. S2CID 228975770.
  5. ^ Curtis, Heber Doust (1903) [1901-03-27]. "On the Limits of Unaided Vision". Lick Observatory Bulletin. 2 (38). University of California: 67–69. Bibcode:1903LicOB...2...67C. doi:10.5479/ADS/bib/1903LicOB.2.67C. PMID 17800603.
  6. ^ "Satellite and Flare Tracking". Retrieved 19 December 2020.
  7. ^ "IAU's statement on satellite constellations". International Astronomical Union. Retrieved 3 June 2019.
  8. ^ "Light pollution from satellites will get worse. But how much?". astronomy.com. 14 June 2019. Retrieved 7 November 2019.
  9. ^ "SpaceX Starlink satellite constellation astronomy light pollution". 29 May 2019. Archived from the original on 29 November 2020.
  10. ^ Bakos, Gaspar. "Light pollution from Satellites".
  11. ^ Montgomery, Marc (18 November 2020). "Astronomers vs tech giants in space". Archived from the original on 29 November 2020.
  12. ^ "SATCON1 Report". 25 August 2020.
  13. ^ "Why do mega constellations matter to the Dark Sky community" (Press release). 27 December 2019.
  14. ^ Lawler, Samantha (17 November 2020). "SpaceX's Starlink satellites are about to ruin stargazing for everyone".
  15. ^ Venkatesan, Aparna; Begay, David; Burgasser, Adam J.; Hawkins, Isabel; Kimura, Ka’iu; Maryboy, Nancy; Peticolas, Laura (6 December 2019). "Towards inclusive practices with indigenous knowledge". Nature Astronomy. 3 (12): 1035–1037. arXiv:2009.12425. Bibcode:2019NatAs...3.1035V. doi:10.1038/s41550-019-0953-2. S2CID 212942611.