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Even Earth's mightiest telescopes aren't up to the task of imaging Apollo lunar landing sites. A lack of resolution is the biggest reason why:
Back in the early 2000s, when I was butting heads seemingly every week with people who believed the Apollo moon landings were faked, such individuals would pull out an argument they thought was their ace in the hole: If NASA's Hubble Space Telescope is powerful enough to see the intricate details of distant galaxies, why can't it see the Apollo astronaut boot prints on our own moon?
Like most conspiratorial thinking, this argument seems persuasive on its surface but falls apart under the slightest scrutiny. Those taken in by it have a misunderstanding of two things: how telescopes work and just how big space is.
Many people think a telescope's purpose is to magnify images. Certainly manufacturers of inexpensive (read: cheap) telescopes love to market them as such: "150x power!" they print in huge lettering on the box (along with highly misleading photographs from much bigger telescopes). While magnification is important, a telescope's real strength is in its resolution, however. The difference is subtle but critical.
Magnification is just how much you can zoom in on an object, making it look bigger. That's important because while astronomical objects are physically big, they're very far away, so they appear small in the sky. Magnifying them makes them easier to see.
Resolution, on the other hand, is the ability to distinguish two objects that are very close together. For example, you might perceive two stars orbiting each other—a binary star—as a single star because they're too closely spaced for your eye to separate. You can't resolve them. Looking through a telescope with higher resolution, however, you might be able to discern the separation between them, revealing that they are two individual stars.
But isn't that just magnification, then? No—because magnification only makes things bigger! This is easy to demonstrate with a photograph: you can zoom in on the photograph as much as you'd like, but past a certain limit, you're just magnifying the pixels, and you can't get any more information out of it. To break through that wall, you have to gain resolution rather than magnification.
[...] At its best, Hubble's resolution is about 0.05 arcsecond—a very tiny angle! But how much detail it can see in real terms depends on the target's distance and physical size. For example, 0.05 arcsecond is equivalent to the apparent size of a dime seen from about 140 kilometers away.
That brings us back to the conspiracy theorists and their gripe about spotting boot prints on the moon. Galaxies are typically tens of millions or even billions of light-years from Earth. At those distances, Hubble can resolve objects a few light-years across—tens of trillions of kilometers—at best. So while it looks like we're seeing galaxies in great detail in those spectacular Hubble images, the smallest thing we can see is still tremendously huge.
Meanwhile the moon is only about 380,000 km from us—and from Hubble. At that distance, Hubble's resolution surprisingly limits it to resolving objects no smaller than about 90 meters across. So not only can we not see the astronauts' boot prints in Hubble images but we also can't even see the Apollo lunar landers, which were only about four meters across!
(Score: 5, Interesting) by VLM on Monday September 02, @03:22PM
Generally you can't see people from space, with weird exceptions.
There's a "famous" ESA photo from awhile ago but not too long ago (some years but not some decades), where they had a very-low earth orbit satellite with a very small scope on it, and "a thousand" ESA employees stand in a field in the shape of the ESA logo (which IIRC is super lame, like lower case serif letters acronym) and you can read the logo but you can't really tell its people it could have just been plants or paint. Unless you were told that was made by 1000 people you would assume its something like a flower-bed or mosaic art from an extreme distance. Like not being able to image the individual pixels in this word: esa but being able to read and recognize the "esa".
The three letter agency people have had VASTLY larger classified satellites and they can supposedly resolve people. Note there's a big difference between you expect to see people there and there's a single pixel dot so you say its a picture of a person (a guard at a gatehouse, perhaps) vs a zillion megapixel glamour photo of a model which is somewhat harder to accomplish optically.
Its fair game to take photos of satellites to compare looking the opposite direction and its much cheaper to put a telescope in my backyard than into orbit; its VERY hard for an amateur to get a photo of the ISS unless you are previously told what you're looking at and you're not going to see astronauts smiling and waving or possibly mooning us, at best if you know the ISS you'll be able to ID the pattern of solar panels and radiator panels as being the ISS. Obviously, the air force has much better satellite imaging equipment to look at foreign countries military sats, but its "non-trivial" to get a good pic of a human sized satellite from the ground.