UKH

Assuming this is legitimate, it's quite beautiful (a word I use sparingly, if ever!)

https://www.facebook.com/share/p/Yka1fRcGuDFd9k7f

It was posted to the NASA James Webb Space Telescope (JWST) group.

It's synthetic, from here:

http://earth.imagico.de/view.php?site=everest

Not a single cloud in 200 miles either side of the divide. 

I say its fake from a flight simulator. 

Given that the Webb telescope is at the L2 point, I'm pretty confident that they'd never point it anywhere near the Earth! And if they did, the shadows would be quite different.

Dunno about Webb... but Hubble on the other hand hardware was (sort of) off the shelf, using a type of well used space telescope that points towards the earth, but pointing it in the wrong direction and tweaking it a bit for looking at stars and whatnot. You never know... maybe Webb gets the occasional special task to accidentally look at the earth once in a blue moon?

Hmm, not sure about that. References?

No. Do you know where L2 is? If Webb turned towards the earth, it would be pointing directly towards the Sun with Earth a small black dot in the middle *. Webb carries a big heat shield between it and the Sun/Earth to keep it in the shade and cold. If it did accidentally turn round to face the Sun/Earth I suspect it would be seriously damaged.

* OK, not that small. From L2 Earth is about 1/2 the apparent diameter of the Sun.

Hubble is well known to bear a striking similarity to the NROs KH-11 recon satellite.  I don't know for sure if there's parts commonality but I wouldn't be surprised.

https://en.wikipedia.org/wiki/KH-11_KENNEN

The fact that "KH-11s are believed to resemble the Hubble Space Telescope in size and shape, as they were shipped in similar containers" hardly suggest that either was built with (even sort-of) "off-the-shelf" components. Certainly the optics, sensor and processing systems were new and original in Hubble.

Yes, I believe the sensors and mirror were designed and screwed up by NASA.

Yes, because

1. they didn't want them too similar (or info about Hubble would reveal capabilities of the other satellites)
2. Hubble was optimised for different targets
3. The kh-11 was superceded at that point

And the stubby Hubbles (spares!) were how Hubble would've looked without the optimisation and extension

https://newatlas.com/spysatellite/22813/

You missed out ".. and quite neatly fixed ... " (RL deconvolution -> WFPC2 & COSTAR at al.).

Ah, you may be thinking about the Grace Roman telescope rather than Hubble, which did/does indeed use the re-purposed optics of a military surveillance satellite...

https://en.wikipedia.org/wiki/2012_National_Reconnaissance_Office_space_tel...

Aghh ... Think Grace Roman must have been one of the two "stubby Hubbles"