Re:How satellite ‘megaconstellations’ will photobomb astrono...
by sreevisakh on Thursday August 27, 2020 @11:14AM
(#24294473)
The problem is with the exposure. 1min exposures are common in astrophotography, but astronomers are complaining about the types that need night-long exposure - ones that try to study cosmology, stellar composition etc. Many observations (like SDSS) are also large field observations that observe many objects simultaneously. Even a single streak can ruin an entire exposure. The odds just grow considerably.
Re:How satellite ‘megaconstellations’ will photobomb astrono...
by fingerlocks on Thursday August 27, 2020 @11:39AM
(#24294742)
In digital photography, an exposure of N seconds can be produced from the sum of N/K shorter exposures at K seconds. This is more of a nuisance than a devastating blow.
A 30 arcsec stripe on an (apparently average) 20 arcmin detector is 2.5% of the total area, so it's not a very large area.
Overall, 20000 satellites at any given time cover 20kπ15acsec² of sky area, which is 0.0005% of total sky area, and over 1 second (assuming a satellite speed of 3.6 arcmin per second) it's 0.02424% of the sky, so roughly 1.45% of the surface area of a 1 minute exposure would have to be thrown out. This assumes that satellite streaks don't overlap, with overlap it would be less.