So the JW telescope can see billions of lightyears into the distance/past and see countless galaxies in the focal point of a grain of sand, but when it’s aimed at at Uranus or a closer planet, the photos are very low quality.
Why can’t a telescope that powerful capture a good image inside our own solar system?
I understand it sees different wavelengths to typical telescopes but why can’t it take a sharp photo of the light emitting from the planet that’s not blurry?
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Generally the most detailed images we have of bodies in the solar system are from spacecraft that travelled very close to them. It’s not really possible to beat them with telescopes on or near earth, similar to how it would be difficult for a spy satellite to get a better photo of your house than you can get with a cheap camera. However, it can still be useful to observe the planets with telescopes, since it’s much easier and cheaper than sending a dedicated probe, and there are always things that haven’t been done with previous missions, e.g. different frequencies and spectroscopy. JWST isn’t capable of observing the inner planets because they’re too close to the Sun from its perspective so it can’t see them from behind its sunshield. But it is being used to observe various things further out in the solar system.
> I understand it sees different wavelengths to typical telescopes
That is part of it. Longer wavelengths of radiation inherently undergo stronger diffraction when they enter and pass through a telescope. So you need a bigger telescope to get the same level of sharpness in an infra red image than you would with an optical image.
Also bear in mind that producing images is only part of the purpose of telescopes like this. They also produce stuff like spectroscopy data that is very useful to astronomers but doesn’t really make for pretty pictures.
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