I recently read that the ISS is visible to the naked eye. That’s astounding. According to space.com: “The ISS is therefore a great skywatching target for those living in urban and rural areas alike. Spotting the ISS requires no specialist equipment as it can be seen with the naked eye . All you need to know is where to look and when.”
Kind of on the other end of the spectrum, it’s possible to see a Tardigrade with the naked eye, at least according to americanscientist.org: “In the right light you can actually see them with the naked eye .”
True. And, the ISS isn’t unique in this regard; any orbiting man-made item that’s big enough, and/or reflective enough, can be seen by the naked eye, if you know when and where to look.
In the past, I’ve seen the ISS, as well as Skylab, Space Shuttle Orbiters, and various satellites, including Iridium satellites, without using any optical devices other than my own eyes.
I’m not sure what you mean by saying we are not seeing “the structure itself”. Unless the light is directly emitted, all seeing is reflected light. If I hold my hand up in front of my face, I’m seeing light reflected off it.
To be more clear, you can see a bright pinpoint of light which is the sun reflecting off the solar arrays of the ISS as it flies overhead. You cannot RESOLVE the structure of the ISS itself with the naked eye.
I don’t think anyone thinks I meant you could see the occupants waving down at us. It’s all a matter of degrees. From where I’m at, sitting in my office, I can look out the window and see the license plate of a car in the parking lot. But it’s far away so I cannot resolve the numbers. Can I still consider myself seeing it?
While I see the point you are making, I think there is perhaps a distinction to be made between being able to see only a pinpoint of light, and being able to resolve some shape to the light.
I miss the Iridium satellites. Iridium flashes were fun.
When I was young, one night lying in the back yard, I spotted a faint object crossing the sky very quickly. I think if you were able to follow it from horizon to horizon, in say Kansas, it might have been visible for about 90secs or less. I was duly creeped out.
There’s an official ISS website that, once you tell it where you are (or the nearest town), will tell you when and where to look for the ISS. I’ve been following it sporadically for five or six years and it can be mildly entertaining.
In order to see it, the satellite has to be high enough in the sky at a reasonable time on a cloudless evening, which might happen once a month or more. As LSLGuy said, it looks like a fast-moving, bright planet, and, if your friends are as dumb as mine, they’ll say, “That’s just an airplane.” So, no big deal. But there’s something unusual about it (probably the silence of its passing). It can take up to five minutes to cross the sky, and it’s kind of cool to watch it disappear while considering the height and speed of its flight.
The Andromeda Galaxy is the most amazing (and distant) thing. On a dark and chest night, look for an elongated smudge between the square of Pegasus and the M/W of Casseopea.
You’re looking at a billion stars (and surely planets, and some civilizations) as they were two million years ago!
And anyone there who’s looking at us…is seeing a planet that includes a primate, Australopithecus, that has just started walking upright, but isn’t especially numerous or notable.
In October, 1957, several classmates awoke two hours before sunrise and proceeded to a hill where we saw Sputnik, less than two feet in diameter. These can only be seen when (A) it is dark, and (B) the satellite is high enough to still be in sunlight.