system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do we have the equipment to picture and see cosmos and stars millions of light years away, but can’t just zoom-in to examine and view the surfaces of our interplanetary planets in the solar system?
gpt
There's a limit to how far you can "zoom in" on something to picture it. The maximum resolution is restricted by the wavelength of light used to capture the image. You can compensate by using a larger lens, but even the largest telescopes in the world aren't anywhere near being large enough to have anything close to high-resolution photographs.

This question comes up when people ask why we can't use a telescope to see the flag on the moon which is significantly closer than the planets but still very far away. Turns out just to identify that, you would need a telescope with a lens miles in diameter. If you want to look closely at planets, the lens would need to be larger than the diameter of Earth.

Now there are some neat tricks astronomers can use. Not too long ago, astronomers managed to take a picture of a black hole. The resolution to make this picture indeed would require a lens about the size of Earth, making it seem impossible at first. But what they did is synchronize a bunch of telescopes from all over the world then stitch the resulting data back together in software. Thus they were able to create a picture with sufficient resolution to identify what they were looking at. A similar technique could be used for getting some better precision for imaging other things as well, but it takes a lot of coordination and resources, and while it improves resolution, it still wouldn't compare to sending over a probe with cameras to take pictures at a closer proximity.