Comments by "H. de Jong" (@h.dejong2531) on "Building the Cosmic Eye: The Journey of the James Webb Telescope!" video.

To see the moon landing, JWST would have to be 53 lightyears away, because that's where the light that left the Moon in 1969 is now.
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Scientists adapt to their audience. Audience is American and mostly laymen?->use Imperial units. The actual units used in the design of the JWST are metric.
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JWST is a passive system: it just processes incoming light. There's no way to detect from a distance that this is happening.
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Even the largest telescopes on Earth don't have enough resolution to show objects that small. JWST will be farther away so its resolution when observing the Moon is lower than the best telescopes on Earth. JWST also can't be pointed at the Moon, because that would require tilting the telescope at an angle that exposes the cold side to sunlight. We do have the Lunar Reconnaissance Orbiter, which made photos of Apollo landing sites: https://www.youtube.com/watch?v=Pnhnx95LkCc
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Space is very empty: JWST will encounter micrograms of dust per year, on average. Asteroids are a potential problem: we haven't found all of them yet. But the chance of being hit by an asteroid is very low. Since the beginning of spaceflight, we haven't lost a spacecraft to an asteroid impact yet.
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JWST was built to have robotic refueling as an option. What we don't have yet is a spacecraft that can approach JWST without damaging the sunshield or contaminating the mirrors.
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JWST is optimized for mid-infrared. Those wavelengths are blocked by Earth's atmosphere, so JWST wouldn't see any details. Also, JWST can't be pointed at Earth, because that would expose the cold side of the telescope to direct sunlight and damage the instruments. We don't need JWST to monitor Earth: we have satellites imaging Earth every day. From weather satellites to commercial imaging to espionage.
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