You misunderstand the issue. It’s a significant problem for some kinds of observations and largely irrelevant to others.
Satellites don’t include light sources and there’s nothing to illuminate them when in earth’s shadow. In order to interfere with light based astronomy they need to be outside of earths shadow and someone needs to be actively taking a picture of that chunk of sky. As these satellites orbit close to earth almost the entire sky is clear near solar midnight.
Major ground based telescopes can also add a shutter to block light detection for the fraction of a second a satellite would interfere. Basically at increasing magnification you’re looking at an ever smaller percentage of the sky which means the odds of a satellite, even one of millions, being in the shot for a given second is low. It’s still an issue, but being 99.X% as effective is good enough not to be a major concern.
Where it’s a concern is whole sky observation where you can’t easily add a shutter and losing a significant portion of the sky every night is a real problem. Amateur astronomy has the same basic options, but will often run into avoidable issues.
In most amateur imaging you can trade time for quality. By stacking enough images, satellite trails get averaged out of the final image.
Very high end amateurs get pissy about it because they paid a lot of money for high end equipment to minimize imaging times, but for the rest of us it’s not a huge impediment as we already needed lots of subframes to get high SNR anyways.
Averaging isn't the only option. It's possible to use other image-processing techniques which look at outlier values. This is way outside my area of expertise, but I believe sigma clipping is one of the standard go-tos, see:
This applies not only to satellite tracks, but meteors, cosmic rays, and other artefacts introduced into image capture. The techniques should be generally applicable, though for those who are specifically exploring transitory phenomena, this introduces additional challenges.
That’s an option. However, these satellites provide a predictable path so you don’t needed to detect them from image data. Which means you can even prevent them from showing up on long analog film exposures.
In balance, shorter exposures, stacking, and track-removal is technically easier.
Long exposures made sense when photgraphic plates were a scarce resource, and replacing them risked disturbing the observation.
Stacking is premised on the idea that individual exposures are cheap, and that noise tends to affect a small number of those exposures, in small regions. The same predictability of satellite tracks you name means that they can be removed through image processing rather than brute force (avoiding sky regions, physical masking, interrupting exposures during overflights, etc.).
And the other phenomena I mention (meteors, cosmic rays) are not predictable, and also degrade deep-space images.
Image processing is a great way to get clean pictures but takes you further from direct observation. You could if extremely unlucky remove a supernova from your image not just meteors and cosmic rays.
A supernova peaks over the course of days, and fades slowly over months to years. They also remain static relative to the background stars, as do all astronomical phenomena outside our Solar System, even over the span of a day.[1]
Even a very-rapidly-peaking kilonova (neutron-neutron star collision) though they peak quite rapidly (short gamma-ray bursts, or SGBs, last about two seconds) have durable remnants lasting weeks.
The transient phenomena discussed here occur largely at the scale of a few seconds at most, often far less, and most move across a significant span of sky within that time.
More likely is that a meteor impact on the Moon (or other Solar System body) might be missed, but those are sufficiently small targets that interference such as we're discussing would not be a significant noise source. Space-based observation of, e.g., comet collisions with Jupiter or Saturn would eliminate LEO satellite noise entirely, though cosmic ray interference would remain a concern.
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Notes:
1. An object moving at 0.99c at the distance of the nearest star, 4 light years, would cover slightly less than 0.04 degrees per day. Much of the Universe is at somewhat greater distance than even this.
Lasers would probably be more practical. Maybe a whole array of lasers w. telescopes? At (say) 500 km, a 20 cm aperture would have a spot size of maybe 50 cm. So let's take that telescope array, hook a kW laser to each one, and roast some LEO satellites?
(Note: this is not an actual suggestion this be done.)
I know you are joking on this one, as I was on mine. But with people being arrested for shining pet toy lasers at objects, best everyone stay clear of this one.
I’m working on a DaaS startup (drone as a service) so maybe I’ll locate next to you and your customers can blow drones out of the sky and mine will keep having to replace theirs.
If you have to yeet space trash to a gravitational well, Jupiter is probably the more attractive option. Lower delta-V, still a large well, and so long as you get reasonably close, orbital decay should solve the problem eventually.
For de-orbiting LEO satellites, electrodynamic tethers is probably the most viable active method:
"Study on electrodynamic tether system for space debris removal"
It’s worth noting that the latest trillionaire lowered launch costs by ~10×. It has never been cheaper to launch a telescope into space. I’m surprised that no universities have launched their own space observatories. Harvard has a $50 billion endowment, but all they ever seem to spend it on is more administrators. They could launch a dozen space telescopes without making a dent.
sky will be constantly twinkling, will be weird
we'll have to switch to space telescopes above LEO
https://satellitemap.space