We don't want to
manipulate pixels; the goal is not to produce pretty pictures of known things. The goal is to collect as much data as possible about things which are not well understood (because, in part, of a lack of data), especially those that are time-varying on short human timescales.
The objects in question are often extremely faint, and even if one knows a lot of the details of periodic noise, removing the noise does not recover the faint signal.
> baffling
Stand by, there will be lot of professional science communication on this topic in due course.
> moon, 1%, ...
Suppose right now at the very limb of the sun we detect an extremely interesting light curve that is clearly not extragalactic yet still atypical of supernovae, but know that it is in the process of moving directly behind the sun (from our perspective). How do you propose to remove the sun from the image of the suspected supernova?
Here's a list of solar-system objects that moved directly behind the sun in 2019: https://sungrazer.nrl.navy.mil/index.php?p=transits/transits... This Christmas would have been an interesting time for 2010: The Year We Make Contact's great black spot of Jupiter to appear.
The moon also occults Jupiter fairly regularly. If Jupiter was doing something strange behind the moon, think of the loss for all the Earth-based observatories. Or would it be trivial for them to faithfully reconstruct the unusual behaviour of Jupiter?
Yes, the sun and moon are slow-moving, bright, and high-solid-angle obstructions compared to any spacecraft. However, so is Jupiter and a galactic supernova, and neither of them are usually interestingly variable on the scale of a glitching millisecond pulsar (for example) or the electromagnetic counterparts to a gravitational wave detection.
In short
> algorithms to erase satellite trails
are doing cosmetics, not astronomical or astrophysical research.
And if cosmetically you erase the wrong pixel, you miss out lots of observation time of events like https://en.wikipedia.org/wiki/ASASSN-15lh#Discovery and end up regretting missing early data (as in e.g. SN 1997D).
http://www.astronomy.ohio-state.edu/asassn/index.shtml exists to avoid missing out on such things again, and if you have a thick skin, there's https://twitter.com/SuperASASSN
A recent tweet is interesting: 'This is, by the way, a discovery made in "astronomical twilight" - one way Itagaki and other amateur astronomers can discovered such events before professional astronomers is by observing fields (galaxies) quite close to the Sun.' (although that's in large part because bigger observatories deliberately aim away from the sun, because it's very noisy and its luminosity may damage sensitive detectors).