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They reflect sunlight for some period of the evening and morning, before the sun is shining where you are and illluminating the sky too much.
so not in the middle of the night.
I sit in my hot tub at night and see 1-2+ satellites go over every single time I'm out there. Which also makes me wonder how many of the shooting stars I've seen recently are just old starlinks burning up.
How do you spot a satellite? I've never seen one.
You probably just thought it was a star or a plane. They move but relatively slowly (even a fast LEO sat will cover the sky in about 5 minutes). They look just like a star apart from moving slowly. Depending on angles they can look pretty dim, especially the latest SpaceX sats. But the ISS is usually really bright because it's so huge and technically it's also a satellite.
You can tell them apart from a plane because they don't flash.
Edit: But yes there are several conditions that need to be met to see them like the other posters have mentioned. But every clear night near dusk or dawn you will see sats for sure. There are just so damn many in LEO now.
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The speed of light in a vacuum is roughly 50% higher than the speed of light in fiber.
I will note that this is the case for conventional fiber-optic cable. The newer hollow-core fiber cables transmit light at nearly c. As far as I know hollow-core has not seen wide-spread use, but it will be interesting if trans-continental connections switch over.
This would be huge for realtime gaming across continents.
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That doesn't seem right, why would they be bright?
That's a very good question. I'm sure of what I've seen, many times over years: I can tell you that they look like stars - so much that I need a reference point, an actual star or planet, to verify they are moving and not a 'stationary' star (judging movement being otherwise very difficult at that distance). They move very steadily, horizon to horizon, or as far as I can track them. A wild guess, based on memory, is…
Yup 5-10 minutes is right. It depends on the orbit altitude and the height of the pass.
You can use sat tracker apps to identify which one you're seeing. I do this sometimes because I'm a ham radio operator and I track the one I want to use sometimes with a directional antenna.
> No way a star is moving that fast relative to other stars
No star moves relative to other stars when viewed from earth. They are all so far away they appear static. The starscape rotates as a whole (well it doesn't, the earth does, but to the observer it seems that way), but relative to each other they absolutely don't move.
If they do move, it is definitely a sign to stop drinking :) :)
> Asteroid? That seems hard to believe, due to size and illumination.
Also asteroids move way faster across the sky than a satellite. And they're rare except during that time of the year when they're really common.
> Comet? Are there lots of tiny ones? I never see tails.
Comets are incredibly rare in this galactic neighbourhood.
> and Earth's horizons. Asteroid? That seems hard to believe, due to size and illumination. Comet? Are there lots of tiny ones? I never see tails.
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1. The satellite needs to be passing overhead at an angle where you can see it, and clear skies etc. 2. The sky needs to be dark enough to see it (so twilight or night) 3. The satellite needs to be illuminated by the sun. 4. The satellite needs to reflect enough light that you can see it. Basically this happens just before sunrise, and just after sunset. So the ground and sky are dark (allowing you to see through the…
> Basically this happens just before sunrise, and just after sunset. I've seen plenty of satellites in the middle of the night, from very dark areas (wilderness). They look like stars, only they move more quickly. These observations go back a decade, at least.
Higher orbits are visible for longer, due to the angles involved: because they're so high, such satellites can remain illuminated with the Sun further below the horizon. The Moon is the most extreme example: it's almost never in Earth's shadow.
I hate that PCMag ignores browser preferred language lists. It switches the language on my geo IP address which is a language I cannot read.
My understanding of the state of the art of inter-satellite optical links is that they have only been used between satellites that are basically in the same orbital plane and in more or less the same orbit. That is, the angle from one satellite to the other changes very very slowly, so that the optics don't have to do much tracking -- and consequently satellites can only form an optical link with other satellites tha…
> “Another really fun fact is that we held a link all the way down to 122 kilometers while we were de-orbiting a satellite,” he said. “And we were able to downstream the video.” > For the future, SpaceX plans on expanding its laser system so that it can be ported and installed on third-party satellites. The company has also explored beaming the satellite lasers directly to terminals on the Earth’s surface to deliver…
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> “Another really fun fact is that we held a link all the way down to 122 kilometers while we were de-orbiting a satellite,” he said. “And we were able to downstream the video.” > For the future, SpaceX plans on expanding its laser system so that it can be ported and installed on third-party satellites. The company has also explored beaming the satellite lasers directly to terminals on the Earth’s surface to deliver…
So what happens to the laser beam when there are clouds?