So you can search this sub for "how do cameras work" for more detail, but you need the TL;DR: that photography is literally "capturing light". And the more massive your... light capture device, the more light you're going to capture. So being a "massive telescope" really helps.

You know how you see long exposure images? That's a camera keeping the shutter open and absorbing more light as it streaks by.

These massive telescopes can keep the "shutter" open for ages, and can move around so they're pointing at the same patch of sky. That way get sharp images rather than streaks.

There's also no atmosphere in space to distort things.

Finally, a lot of post-processing happens after images are taken.

EDIT to add that for planets in the solar system, we actually send spaceships over to take up-close pictures.

Some of what you see is long exposure photography, where the camera is attached to a telescope that moves with the rotation of the Earth. Some photography you see of distant galaxies, etc are not photographs, or are only infrared and the astronomers add false color later.

Don't overestimate how detailed they are. They're showing a lot of features, but those features are very, very large.

When you see swirls in the atmosphere of Jupiter, like on this page: https://solarsystem.nasa.gov/planets/jupiter/in-depth/

Be sure to look at the size comparison: those details you're looking at are the size of Earth. Something as small as, say, Alaska, you probably wouldn't be able to see, because the pictures aren't that detailed.

>I know we get them through massive telescopes…. But how do they capture images so far away? How do they work?

Actually, quite a lot of them are from very light telescopes - ones attached to interplanetary probes sent to explore the planets. Quite often these images are mosaics, stitched together from multiple pictures.

To add to the last bit: part of the post processing is taking advantage of the fact that celestial objects move so slowly they might as well be static.

Now, when cameras take pictures, sometimes there are tiny "blips" in the photo (for a myriad of reasons) which creates noise in the photo (slight colour irregularities; you'll see a lot of noise in low-light photography with your cell phone, for example).

But since objects in space don't really move at all over days/weeks/months/years (depending on what we're talking about) you can take as many photos as you want.

Aside: Even crazy long exposure photographs. With a computerized motor that matches the rotation of the Earth, you can take photos with exposure times of hours.

Then you put all those images into computer software that compares them all. If most of the images agree on a pixel, then it's probably "correct", so any "blips" of noise can be eliminated (or at least drastically reduced).

You can also use different lenses and filters to only look at specific frequencies of light one by one, then combine them all using computers. And do all the exposure and stacking techniques above to make the individual spectrums more clear.

Combine the above, and you can get incredibly clear photos, even with a backyard telescope (with the right tools and a lot of patience!)

Another thing I didn't see above is using multiple radio telescopes that are very far apart. Looking at some lower frequencies of electromagnetic radiation, they can effectively combine their images to make a "virtual" telescope that's way bigger than they are.

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You can also read this fun article that explains it here: https://www.theverge.com/2022/10/10/23393194/nasa-image-processing-jwst-astrophotography

Thank you for the detailed explanation. I am trying to understand how scientists can be certain that the light they capture, especially from objects that are thousands/millions of light years away that the light is indeed from those objects and is not contaminated by other light? Again, kindly eli5!

I mean, you'd see the other light (: