News for hackers. Stuff that matters.
Re:How satellite ‘megaconstellations’ will photobomb astrono... by scoot on Thursday August 27, 2020 @05:42AM (#24291778)
I can periodically see with the naked eye what appear to be "moving stars" (about the same approximate brightness as an average star), and appearing to orbit the earth (moving in a "straight" line across the sky).

Can I assume that these are satellites?

Re:How satellite ‘megaconstellations’ will photobomb astrono... by sreevisakh on Thursday August 27, 2020 @10:27AM (#24294010)
What you describe does sound like a satellite - but it could also be a rocket body. If it moves slowly enough and lasts long enough to for you to show it to another person, it probably is a satellite or rocket body. As mentioned, it also travels straight and shows up close to dawn and dusk. You can get predictions for sighting in your area from Heavens Above (https://www.heavens-above.com/).

It gets more interesting though. Most satellites have brightness that changes slowly as moves - due to change in illumination. But occasionally, you would find ones which dim and brighten in cycles. This indicates that the object has no attitude control and is tumbling in space. That could be a dead satellite or a rocket body. Rocket bodies are spent rocket stages which loiter in space for a while after completing its mission. Then there are flares. Some satellites (like the old Iridium constellation) occasionally reflect sunlight right at you (unlike diffuse reflections in normal sats). This is a very local event. Some flares can get brighter than any planet or stars.

It's also possible to identify what you are seeing. That used to be my hobby. You would record the time it appears, how high it gets, the direction in which it flies, how bright it gets and when it disappears. With experience, you can get a good enough estimate of the brightness (magnitude) and angles even without instruments. You would then compare it against satellite predictions like Heavens Above to identify the exact object. The one I was thrilled about was a Russian satellite powered by a nuclear reactor (a fission reactor, not a decay battery like RTG). Some of them are still in LEO (https://en.wikipedia.org/wiki/List_of_nuclear_power_systems_...).

Re:How satellite ‘megaconstellations’ will photobomb astrono... by sneak on Thursday August 27, 2020 @05:46AM (#24291806)
Yes, especially if they are just after dusk or before dawn. Spotting satellites is a common thing.
Re:How satellite ‘megaconstellations’ will photobomb astrono... by scoot on Thursday August 27, 2020 @05:58AM (#24291909)
Yes, an hour or so after dusk. Guess that's what they are then!
Re:How satellite ‘megaconstellations’ will photobomb astrono... by DavidKarlas on Thursday August 27, 2020 @06:13AM (#24292025)
You can even see shape(solar panels) of ISS with naked eye, pretty mind blowing...
Re:How satellite ‘megaconstellations’ will photobomb astrono... by nsilvestri on Thursday August 27, 2020 @09:41AM (#24293574)
No you can't. That's beyond the biological capabilities of the human eye, even if you have absolutely perfect vision.
Re:How satellite ‘megaconstellations’ will photobomb astrono... by dsun179 on Thursday August 27, 2020 @05:46AM (#24291814)
Sattelites appear way faster then what you expect from a moving star or a plane.
Re:How satellite ‘megaconstellations’ will photobomb astrono... by scoot on Thursday August 27, 2020 @09:42AM (#24293578)
Well, I don't expect starts to move (relative to each other), and angular velocity is harder to compare with a moving plane that may not be passing directly overhead and so appears slower, but yes, faster than a plane.
Re:How satellite ‘megaconstellations’ will photobomb astrono... by gppk on Thursday August 27, 2020 @05:45AM (#24291803)
They look something like this - https://explainingscience.org/2020/01/29/spacex-starlink-sat...

If you google starlink satellites you can see more images

Re:How satellite ‘megaconstellations’ will photobomb astrono... by scoot on Thursday August 27, 2020 @05:57AM (#24291901)
Not a chain, just an occasional individual one.