5 ms·

sadly won't be possible for anything serious next decade as each space trillionaire and country launches their own 10,000+ constellations sky will be constantl

by ck2 4mo ago

sadly won't be possible for anything serious next decade as each space trillionaire and country launches their own 10,000+ constellations sky will be constantly twinkling, will be weird we'll have to switch to space telescopes above LEO https://satellitemap.space https://satellitemap.space

zippyman55 4mo ago
I’m seeking funding to open up a rail gun ranch where you can sit in your lawn chair and blow satellites out of the sky.
- tedd4u 4mo ago
  Probably legal in Texas? If it's directly over "your land?"
  - dylan604 4mo ago
    If your application says it is meant to hunt feral hogs, then they will allow it.
    - zippyman55 4mo ago
      This may be a good plan B pivot! Join now and get a free lawn chair!
    - throwup238 4mo ago
      Feral hogs IN SPAAAAACE!
- ck2 4mo ago
  I'm thinking of "space roombas" that glide around and bump all the sats in LEO into the atmosphere like a game of pool Only problem is they are toxic as they burn up and create a lot of pollution * https://www.bloomberg.com/graphics/2025-space-orbit-satellites-pollution/ https://www.bloomberg.com/graphics/2025-space-orbit-satellit... (too bad gravity is impossible to overcome cheaply or do the opposite and yeet into sun)
  - dredmorbius 4mo ago
    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" <https://www.sciencedirect.com/science/article/abs/pii/S0094576504002176 https://www.sciencedirect.com/science/article/abs/pii/S00945...>
- adrianN 4mo ago
  Kessler‘s farm?
- pfdietz 4mo ago
  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.)
  - zippyman55 4mo ago
    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.
    - pfdietz 4mo ago
      It's more a thought experiment on perhaps how easily this could be done.
- ninjalanternshk 4mo ago
  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.
  - zippyman55 4mo ago
    I like where you are going with this. Can you offer “hardened” drones for the advanced players?
Retric 4mo ago
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.
- theresistor 4mo ago
  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.
  - dredmorbius 4mo ago
    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: <https://www.gnu.org/software/gnuastro/manual/html_node/Sigma-clipping.html https://www.gnu.org/software/gnuastro/manual/html_node/Sigma...>. More generally, you're clipping outliers: <https://www.gnu.org/software/gnuastro/manual/html_node/Clipping-outliers.html https://www.gnu.org/software/gnuastro/manual/html_node/Clipp...>. 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.
db48x 4mo ago
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.

by ck2 4mo ago

zippyman55 4mo ago

I’m seeking funding to open up a rail gun ranch where you can sit in your lawn chair and blow satellites out of the sky.

tedd4u 4mo ago
Probably legal in Texas? If it's directly over "your land?"
- dylan604 4mo ago
  If your application says it is meant to hunt feral hogs, then they will allow it.
  - zippyman55 4mo ago
    This may be a good plan B pivot! Join now and get a free lawn chair!
  - throwup238 4mo ago
    Feral hogs IN SPAAAAACE!
ck2 4mo ago
I'm thinking of "space roombas" that glide around and bump all the sats in LEO into the atmosphere like a game of pool Only problem is they are toxic as they burn up and create a lot of pollution * https://www.bloomberg.com/graphics/2025-space-orbit-satellites-pollution/ https://www.bloomberg.com/graphics/2025-space-orbit-satellit... (too bad gravity is impossible to overcome cheaply or do the opposite and yeet into sun)
- dredmorbius 4mo ago
  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" <https://www.sciencedirect.com/science/article/abs/pii/S0094576504002176 https://www.sciencedirect.com/science/article/abs/pii/S00945...>
adrianN 4mo ago
Kessler‘s farm?
pfdietz 4mo ago
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.)
- zippyman55 4mo ago
  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.
  - pfdietz 4mo ago
    It's more a thought experiment on perhaps how easily this could be done.
ninjalanternshk 4mo ago
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.
- zippyman55 4mo ago
  I like where you are going with this. Can you offer “hardened” drones for the advanced players?

Retric 4mo ago

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.

theresistor 4mo ago
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.
- dredmorbius 4mo ago
  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: <https://www.gnu.org/software/gnuastro/manual/html_node/Sigma-clipping.html https://www.gnu.org/software/gnuastro/manual/html_node/Sigma...>. More generally, you're clipping outliers: <https://www.gnu.org/software/gnuastro/manual/html_node/Clipping-outliers.html https://www.gnu.org/software/gnuastro/manual/html_node/Clipp...>. 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.

db48x 4mo ago

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.