Don’t know why this popped into my head, but here goes. Imagine I’m launched from Earth straight up to the altitude of the ISS. I’ve then got a jet-pack that allows me to hover there. So I’m going to have the same rotational speed of the Earth, but otherwise be floating in space.
Say I’m 1 meter to the side of the ISS as it passes by (what I mean is that I’m on the “sidewalk” and the ISS is orbiting on the “road”). Now, the ISS is moving about 8 km a second, which is way faster than a bullet. I can’t see a bullet, now can I? So I figure I’m not going to see the ISS. But it is much bigger than a bullet, and I presume light is going to glint off (assuming we’re on the sun’s side of the Earth). So am I going to see a streak of light going by? Or am I just going to see nothing?
Size matters. You can’t see the bullet not only because it is so fast, but also that it is so small.
The ISS is 73 meters long. If it is moving at 8000 meters per second, some part of it will be next to you for almost a hundredth of a second. I imagine that is quite long enough to notice, even if you can’t make out any details.
By comparison, a car moving at 100 km/hr is going about 3 meters per second, or 30 cm in a hundredth of a second. Suppose that’s the diameter of the hubcap of the car that’s passing you at that speed. Can you see the hubcap? I don’t know. Anyone want to experiment?
Even if you don’t see it exactly as it passes by, you’ll definitely see it coming and going. It’s going to approach you nearly directly head-on, meaning that it’s going to be nearly stationary in your field of view for a good time. Likewise, for when it’s receding.
One day in the early morning, around 6:30, it was still dawn and the sun hasn’t quite risen yet. I was on the way to work. I looked up and saw a pair of bright starts quite close together in the clear sky. It was the space shuttle catching up to the ISS.
If these “stars” didn’t appear to be moving, then they weren’t the ISS/shuttle. A few years ago I used NASA’s ISS tracker to find out when it would be passing overhead. When I looked for it, its path matched their prediction: it appeared directly south of me, and moved across the SW quadrant of the sky, dropping below the horizon a point directly west of me. It was visible only for about 90 seconds.
TL,DR: the ISS is not in a geosynchronous orbit, and so it will appear to be moving quite rapidly compared to the stars in the background.
It will have to be a very powerful jet-pack to make you hover stationary - you are also aware, that straight up is coming from a rotating planet.
Do you mean, hovering above a certain point above earth?Then watch this Video from the ISS. You would have to move at earths rotational speed and keep pushing yourself up.
The ISS goes around the earth something like a little more than 15 times per day, every 90/ish minutes and the ISS does not pass over the “same” spot on earth every time - you get an idea how it passes here. So, you would have to move around quite a bit to be 1 meter close - which is not straight up anymore.
However, since its big and nothing is impairing your view - you can see it coming and going from a very far distance.
Actually, it’s rather easy. In the case of, say, a ,45-caliber pistol bullet (reasonably large, not especially fast), all you need do is stand more or less behind the shooter with decent lighting (sun behind you).
Rifle bullets are faster and thus harder to see, but if you are behind the shooter with good lighting, looking through a telescope trained on the target, you can readily see bullets as they “fall” into it (at any decent range, a bullet’s mid-range height is well above the direct line from muzzle to point of impact).
Here you go. This is for the US. Pick your state and then the city nearest where you live. You should be able to reset the location for other parts of the world too, but I haven’t tried.
This. 100 km/hr is about 60mph. Professional athletes can easily throw balls that fast.
Can you see a baseball professionally pitched past your head? (non-US folks insert appropriate sport & ball type here). Of course you can. So the angular size & rate are visible.
As many others have noted, the ISS would be obvious as it got bigger and bigger coming all-but straight towards you. As it went by it’d be huge, the size of an airliner. No you couldn’t swivel your head or eyes fast enough to follow it as it passed you.
So I’m just trying to visualize this. I’d be floating there, and about two seconds before the ISS passed me, I’d see something about the size of a star in the distance, yes? Then over the next two seconds, it would seem to explode to the size of a passenger jet. I’m guessing I wouldn’t be able to see anything in detail, so would it look basically like huge flash of light?
Follow-up question: if something the size of the ISS was moving at 99% of the speed of light, would I still see it as it passed me by in the situation I described?
Indeed. I’ve seen it many times. But you gotta concede that tracking something moving quickly from a distance is a lot different from tracking it close up. First hand, I can tell you the experience of tracking a baseball moving 70 mph from the batter’s box is a lot harder the tracking a baseball moving 100 mph from the stands!
I saw it the other evening, around 9 PM, at Charleston, SC. (I think it was Thursday evening. It moved quickly from SW to NE and was visible for only 6 minutes.) It appeared blue, with two appendages, one at the front and the other at the rear (through my binoculars). I’d like to hijack this post by asking why did it appear blue (atmospheric conditions?) and what were those appendages.
This is not the question the OP is asking. He is asking what the station would look like in a hypothetical situation where he is hovering in a stationary spot directly next to the station as it passes by in orbit.
The two appendages are no doubt the twin solar arrays for the ISS. Found this picture of the ISS taken from the ground through a telescope on the ISS Wikipedia page. You got a likely-fuzzier version of that image via your binoculars, of course, it all depends on how the station is configured from your vantage point as to its exact apparent shape. Not sure why you saw it as blue though, maybe a side-effect of the binoculars you were looking through?
The only thing that I can add is being on the bridge of a Navy ship with F/A-18s were doing low altitude flyovers. Now the straight on angle of an F/A-18A is pretty small, but you could still see it if you knew what direction is was on. But when it was flying over it was virtually impossible to see for more than small fraction of a second and was very hard to pick up on the other side for some reason.
Not quite; it would appear as a star in the distance for much longer than two seconds. You would be able to see it as a bright star when it was at least 200 miles away, so you’d see it coming for at least 40 seconds (especially if you were above the dark side of the Earth, but the ISS were in full sunlight, which is the normal situation when observing it from the Earth;s surface).
