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?
In: 11
Telescopes aren’t designed to magnify so much as capture as much light as possible in order to brighten dim phenomena to a point at which we can usefully observe them. Telescopes are like light buckets: the wider the bucket, the more light it captures in a given time period.
A telescope’s primary optical element (usually a mirror, but can also be a lens) determines the instrument’s magnification. The telescope’s focal length is chosen based on the class of targets it will be used to observe, then it’s mirror/lens is constructed to have the greatest possible areal.
In terms of relative apparent size, planets cover a miniscule portion of the sky compared to more distant (but much larger) deep-space phenomena. So even though planets are physically closer and far brighter than deep space objects, we simply cannot resolve their details past a certain point because the resolution needed to display them is finer than the wavelength of light itself by the time it reaches the telescope.
We don’t use telescopes to make deep space phenomena bigger; we use telescopes to make deep space phenomena *brighter*, or at least less dim.
Latest Answers