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The satellites can be seen with the naked eye. There's a visible pass over San Francisco tonight around 6:15 PM: https://james.darpinian.com/satellites/?special

The satellites can be seen with the naked eye. There's a visible pass over San Francisco tonight around 6:15 PM: https://james.darpinian.com/satellites/?special=starlink-latest https://james.darpinian.com/satellites/?special=starlink-lat... The viewing window is actually pretty small. For most of the night the satellites are not visible because they are in Earth's shadow. There is an impact on astronomy but it is being overstated by journalists hungry for yet another "Big Tech bad" story.

growlist 7y ago
> The impact on astronomy is being overstated by journalists hungry for yet another "big tech bad" story. Indeed, and let's not forget that Elon has upset a lot of applecarts with SpaceX and Tesla.
petschge 7y ago
Depending on source class and telescope location it ruins between 1/3 and 1/2 of the available observing time. Are you willing to pay $1 more in taxes to to fund the extra telescopes we need to make up the short fall? Please write to your representatives and senators if you do.
- modeless 7y ago
  Yes, I am for building more telescopes, and especially space based ones which should become much cheaper to launch when SpaceX's Starship is ready.
  - petschge 7y ago
    Space based works for optical, but not all other wave length. For example it will also reduce the sensitivity of air cherenkov telescopes that detect gamma rays and that can not be moved to space.
    - xur17 7y ago
      Why can't those be moved to space?
      - rtkwe 7y ago
        They are imaging the flashes as the relativistic particles slam into our atmosphere. No atmosphere, no flash. https://en.wikipedia.org/wiki/IACT https://en.wikipedia.org/wiki/IACT
      - HorstG 7y ago
        Because cherenkov radiation is only observable in a transparent medium like air or water. Space doesn't work because the speed of light in space equals the speed of light in vacuum, therefore no cherenkov radiation.
        Taniwha 7y ago
        Couldn't they look down?
        HorstG 7y ago
        Cherenkov telescopes for neutrinos do look down for reasons of schielding. Neutrinos can pass the earth, other particles not so much. But those are a special case, air cherenkov telescopes are looking for "less weird" particles like photons or protons. Those can only be seen looking up, since the primary particles moving down focuses the cherenkov light down in a narrow cone.
        petschge 7y ago
        The Cherenkov emission is boosted in the direction of travel, i.e. downward. And there are too many lights on the surface of the Earth.
        m4rtink 7y ago
        While this certainly requires non trivial large scale space engineering, you should be able to build in in principle. Basically a big bubble filled with the most useful gas for this + bunch of photodetectors inside at the appropriate places. You could also make the whole detection chamber much larger, than the ~30 km (?) of reasonably thick atmosphere you get on Earth.
  - gizmo385 7y ago
    Satellites and space-based telescopes are still monumentally expensive even if you ignore launch cost. The James Web Space Telescope has cost almost 10 billion dollars in development and won't even launch until (unless the schedule slips again) next year.
    - deleted 7y ago
      [deleted]
    - modeless 7y ago
      One of the reasons JWST is expensive is its complex folding mechanism. Starship could launch a mirror bigger than JWST's in one piece. Another reason is that they're only launching one and it has to work perfectly the first and only time it's launched. That level of reliability in a one-off product is incredibly expensive to achieve. With dramatically cheaper launches it would make sense to launch a much larger number of less reliable but much less expensive telescopes. Another reason is politics, but SpaceX can't solve that one.
      - pawelk 7y ago
        > it would make sense to launch a much larger number of less reliable but much less expensive telescopes What if... SpaceX made up for the pollution they introduce by making the Starlink satellites look up the other way and push the captured data back to earth? The lens and CCD would be small, but with the massive volume (and clear sky) it could add up. Like the amateur set ups using an array of consumer grade cameras.
    - FeepingCreature 7y ago
      Space-based telescopes are expensive in part because launches are expensive, making it more effective to spend a lot of money on single telescopes.
prpl 7y ago
No, it’s not. This hurts survey telescopes and it’s an orders of magnitude issue. A rule of astronomy is that if you can see it with your eyes near a city than it’s really really fucking bright, if you can see it with your eyes in the wilderness after your eyes have adjusted for 10 minutes, than it’s still extremely bright. Bright, fast-moving things are pretty terrible. Even if Starlink doesn’t kill astronomy, the next 4 companies with similar deployment will definitely exclude types of sciences and ruin billions of dollars of investments in new observatories.
- wnkrshm 7y ago
  Also, asteroid detection may be hampered - there is still a significant contribution of 'amateur' observations to detecting them.
- bryanlarsen 7y ago
  It's bright because it's in a low orbit and a lot closer to us. Because it's in a low orbit it's in the earth's shadow for most of the night. It's not bright while in shadow.
- ogre_codes 7y ago
  Saying it will "Kill astronomy" is pretty hyperbolic. It will likely affect some earthbound astronomy significantly, but much (most?) of the most important work in modern astronomy is satellite based. I'm on the fence on this whole issue. It's not exactly clear what impact it will have on astronomy. Nor what impact it will have on making the internet pricing and availability. Where I used to live, the only options for internet access were expensive and really bad, the positive impact this might have is potentially quite big. It's hard with a story like this to suss out what the long term effects will be so it's a big grey area.
  - rtkwe 7y ago
    Most astronomy is long exposure which the eventual mega constellation is particularly harmful too because there's no way currently to deal with the light reflecting off them.
esaym 7y ago
That's an amazing site, thanks!
scrumbledober 7y ago
hopefully the clouds clear up before then!
reaperducer 7y ago
The viewing window is actually pretty small. Tonight. And what about when SpaceX gets all 11,000 satellites up there? And then Amazon's constellation. and then all the other American companies planning to do the same thing. And the European companies. And the Chinese companies and the Indian companies, and on and on and on. Dropping a piece of plastic in a lake isn't a big deal. Until it's 11,000 pieces of plastic. And then hundreds of other people do it, too.
- modeless 7y ago
  The viewing window is the same length no matter how many satellites there are at the same altitude, because Earth's shadow is the same for all of them.
- astrodust 7y ago
  One step closer to a sky that looks like a television tuned to a dead channel.
pfdietz 7y ago
Which telescopes are observing at 6:15 pm local time? The satellites are not in sunlight unless the sun is not that far below the horizon.

growlist 7y ago

> The impact on astronomy is being overstated by journalists hungry for yet another "big tech bad" story. Indeed, and let's not forget that Elon has upset a lot of applecarts with SpaceX and Tesla.

petschge 7y ago

Depending on source class and telescope location it ruins between 1/3 and 1/2 of the available observing time. Are you willing to pay $1 more in taxes to to fund the extra telescopes we need to make up the short fall? Please write to your representatives and senators if you do.

modeless 7y ago
Yes, I am for building more telescopes, and especially space based ones which should become much cheaper to launch when SpaceX's Starship is ready.
- petschge 7y ago
  Space based works for optical, but not all other wave length. For example it will also reduce the sensitivity of air cherenkov telescopes that detect gamma rays and that can not be moved to space.
  - xur17 7y ago
    Why can't those be moved to space?
    - rtkwe 7y ago
      They are imaging the flashes as the relativistic particles slam into our atmosphere. No atmosphere, no flash. https://en.wikipedia.org/wiki/IACT https://en.wikipedia.org/wiki/IACT
    - HorstG 7y ago
      Because cherenkov radiation is only observable in a transparent medium like air or water. Space doesn't work because the speed of light in space equals the speed of light in vacuum, therefore no cherenkov radiation.
      - Taniwha 7y ago
        Couldn't they look down?
        HorstG 7y ago
        Cherenkov telescopes for neutrinos do look down for reasons of schielding. Neutrinos can pass the earth, other particles not so much. But those are a special case, air cherenkov telescopes are looking for "less weird" particles like photons or protons. Those can only be seen looking up, since the primary particles moving down focuses the cherenkov light down in a narrow cone.
        petschge 7y ago
        The Cherenkov emission is boosted in the direction of travel, i.e. downward. And there are too many lights on the surface of the Earth.
      - m4rtink 7y ago
        While this certainly requires non trivial large scale space engineering, you should be able to build in in principle. Basically a big bubble filled with the most useful gas for this + bunch of photodetectors inside at the appropriate places. You could also make the whole detection chamber much larger, than the ~30 km (?) of reasonably thick atmosphere you get on Earth.
- gizmo385 7y ago
  Satellites and space-based telescopes are still monumentally expensive even if you ignore launch cost. The James Web Space Telescope has cost almost 10 billion dollars in development and won't even launch until (unless the schedule slips again) next year.
  - deleted 7y ago
    [deleted]
  - modeless 7y ago
    One of the reasons JWST is expensive is its complex folding mechanism. Starship could launch a mirror bigger than JWST's in one piece. Another reason is that they're only launching one and it has to work perfectly the first and only time it's launched. That level of reliability in a one-off product is incredibly expensive to achieve. With dramatically cheaper launches it would make sense to launch a much larger number of less reliable but much less expensive telescopes. Another reason is politics, but SpaceX can't solve that one.
    - pawelk 7y ago
      > it would make sense to launch a much larger number of less reliable but much less expensive telescopes What if... SpaceX made up for the pollution they introduce by making the Starlink satellites look up the other way and push the captured data back to earth? The lens and CCD would be small, but with the massive volume (and clear sky) it could add up. Like the amateur set ups using an array of consumer grade cameras.
  - FeepingCreature 7y ago
    Space-based telescopes are expensive in part because launches are expensive, making it more effective to spend a lot of money on single telescopes.

prpl 7y ago

No, it’s not. This hurts survey telescopes and it’s an orders of magnitude issue. A rule of astronomy is that if you can see it with your eyes near a city than it’s really really fucking bright, if you can see it with your eyes in the wilderness after your eyes have adjusted for 10 minutes, than it’s still extremely bright. Bright, fast-moving things are pretty terrible. Even if Starlink doesn’t kill astronomy, the next 4 companies with similar deployment will definitely exclude types of sciences and ruin billions of dollars of investments in new observatories.

wnkrshm 7y ago
Also, asteroid detection may be hampered - there is still a significant contribution of 'amateur' observations to detecting them.
bryanlarsen 7y ago
It's bright because it's in a low orbit and a lot closer to us. Because it's in a low orbit it's in the earth's shadow for most of the night. It's not bright while in shadow.
ogre_codes 7y ago
Saying it will "Kill astronomy" is pretty hyperbolic. It will likely affect some earthbound astronomy significantly, but much (most?) of the most important work in modern astronomy is satellite based. I'm on the fence on this whole issue. It's not exactly clear what impact it will have on astronomy. Nor what impact it will have on making the internet pricing and availability. Where I used to live, the only options for internet access were expensive and really bad, the positive impact this might have is potentially quite big. It's hard with a story like this to suss out what the long term effects will be so it's a big grey area.
- rtkwe 7y ago
  Most astronomy is long exposure which the eventual mega constellation is particularly harmful too because there's no way currently to deal with the light reflecting off them.

esaym 7y ago

That's an amazing site, thanks!

scrumbledober 7y ago

hopefully the clouds clear up before then!

reaperducer 7y ago

The viewing window is actually pretty small. Tonight. And what about when SpaceX gets all 11,000 satellites up there? And then Amazon's constellation. and then all the other American companies planning to do the same thing. And the European companies. And the Chinese companies and the Indian companies, and on and on and on. Dropping a piece of plastic in a lake isn't a big deal. Until it's 11,000 pieces of plastic. And then hundreds of other people do it, too.

modeless 7y ago
The viewing window is the same length no matter how many satellites there are at the same altitude, because Earth's shadow is the same for all of them.
astrodust 7y ago
One step closer to a sky that looks like a television tuned to a dead channel.

pfdietz 7y ago

Which telescopes are observing at 6:15 pm local time? The satellites are not in sunlight unless the sun is not that far below the horizon.