I recently found this reel on instagram that we have captured a little image/video of the sun.
Given how far the earth is to the moon, could it be possible for us to see the flag on the surface on the moon then if man actually landed on the moon?
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There’s a formula for the limit on what a telescope can see: R = 11.6 / D. “R” is the size of the object in arcseconds (that’s the measure of the angle; 3600arcseconds = 1degree), and “D” is the size of the mirror in centimeters. The James Webb Telescope has a mirror diameter of 6.5 meters, which works out to 11.6 / 6500 = 0.002.
However, there’s something called the Nyquist-Shannon Sampling theorem, which I’m going to skip over explaining but the basic result is that you have to double the answer you got from the first formula, so we get 0.004 arcseconds. So, with the Webb, you could see a baseball from 4000 kilometers. And that sounds pretty good, but the moon is 380,000 kilometers away, which is 95 times as far. In theory, from Earth, the Webb could make out a baseball on the moon if it were 22 feet across, but it would just be a single pixel in the final image; there would be no detail (you couldn’t see the lacing, for example, or read Paul Bunyan’s signature).
/u/Xelopheris has already done the search for flag size, which comes up with 0.002 arcseconds – consistent with the *theoretical* limit of the Webb telescope, but not the *practical* limit.
“But wait!”, you say, “There are bigger telescopes than the James Webb here on Earth!” True, but all the ground-based telescopes have to look through atmosphere, which causes a lot of trouble, and also means you couldn’t see the flags.
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