3 ms·
From Earth, yes. It's called the diffraction limit [1]. With an ideal 1m diameter lens or mirror you cannot resolve features smaller than about 250m on the Moon
by mppm 2y ago
From Earth, yes. It's called the diffraction limit [1]. With an ideal 1m diameter lens or mirror you cannot resolve features smaller than about 250m on the Moon. To capture a sharp 100 Mpx image, you would need a telescope of at least that size. When the aperture grows above 1m, atmospheric disturbances get progressively worse too, which is why all the really sharp imagery comes from satellites around the Moon.
[1] https://en.wikipedia.org/wiki/Diffraction-limited_system https://en.wikipedia.org/wiki/Diffraction-limited_system
- dylan604 2y agoYou are totally ignoring AO, Adaptive Optics[0], that allow for compensating for that atmospheric distortion. If you've ever seen picture of an observatory with a bright laser beaming out from it, that's what it is. It is the capabilities of AO, the cost of building on terra firma vs space platform, and the ability for humans to service the observing platform that leads many astronomers to not be so gung-ho on space based observation platforms in the visible spectrum [0]https://en.wikipedia.org/wiki/Adaptive_optics https://en.wikipedia.org/wiki/Adaptive_optics
- mppm 2y agoI know, but adaptive optics for large apertures also pose a progressively serious engineering challenge. I don't think we could build a 100m diffraction-limited telescope today (on the ground). It would still be useful for it's light-gathering capability, but resolution would not scale proportionally.
- dylan604 2y agoMaking the extremely large primary out of smaller units working together to make an adaptable cohesive unit might be a challenge, but it is doable. This was how SDI was working, it's how DLP tech work[s|ed], it's the same concept that allowed JWST to work.