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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Can’t we see footprints, rover tracks, and even the rover itself left there?
Among the other responses, the flag is also completely white now due to being blasted by solar radiation.
Here’s a less nerdy answer for you. A lot of people forget the size of the Moon. Its diameter is roughly the same width of the USA coast to coast. So imagine yourself standing on the moon (a quarter of a billion miles away). How big of a telescope would you need to see the flag in your neighbor’s backyard?
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.
No, even with the biggest telescope on earth it world be like trying to see the flag ~300km away at naked eye
Source: a telescope enthusiast I met and I belive him
Satellites in space taking pictures of Earth have managed to get like a square meter to one pixel of resolution. So a flag on the surface of Earth being smaller, it would look like a block of colour averaged from the flag and the ground around it. So no not yet, we can not see that flag from Earth. You also should consider how we see things, from light reflecting, now think of a sea urchin growing out into space. Up close those light reflections seem intense, with distance there are massive gaps between them. How can you capture all the light that hit the flag if it is spreading out over distance? You would need a lens the size of Earth, or something special (like software) that can make images and patterns from the diffracted and reflected light with missing pieces. Lot’s of people would claim that’s a digital recreation and not photo or image (not me, all the same thing in the end, your brain is a computer and runs software). So a lot of detailed images of space are not images of visible light wave range radiation, like what our eyes detect, they’re usually some other wavelength, like infrared, and a computer chooses colour gradients based on intensity or absorbance of the infrared, like a see in the dark camera, remember when they were all green, then they were like, let’s make red mean more heat, and it looked different but was the same signal. Green was a more analog display of intensity, the red to blue is software colour coding intensity to make the image easier to pick information out of. X-rays used to be creepy photos of density burned into film proportionally as it blocks x-rays depending on mass and density. Now we computer enhance those images, and they are not true photos, but they better represent what is actually physically inside us. So they’re an illusion of math and computers, but yet more accurate than reality.
Everyone is saying “no”, but this article claims the opposite about the James Webb space telescope: https://www.cbsnews.com/news/james-webb-space-telescope-fun-facts/
I’ve also heard something similar in a speech on the “The royal institution” YouTube channel (there is was about detecting fever of an astronaut on the moon).
Sure, it’s not visible light, but the resolution is not the problem.
If you were looking through a telescope on the moon, imagine how hard it would be to see a flagpole on earth.
Think of when you have a really big photo in photoshop like 20,000×20,000 so theres lots of detail. Then you size it down to 500×500, and you can still make out what the picture is but with much less detail. Once that’s happened, even if you resize it back up to 20,000×20,000 you still won’t be able to see any of the small details even though it’s the same image in the original size.
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