(blush) And I didn't think anyone noticed that out there in Webland... There's an even more subtle point to the UV background. The UV sky was only then being surveyed for the first time, and over most of the sky, there were as yet no other measurements to tell which stars would be UV-bright. This isn't always obvious, since some cool stars have hot companions that are quite faint in the visible. Some of the Apollo 16 exposures were a lot deeper than the ones aimed at Earth, showing very rich Milky Way fields. The spiral galaxy NGC 253 was detected (although with a 20-degree field, not very spectacular), and the Large Magellanic Cloud looks pretty cool in these data. I'm attaching a copy of that one.

(smacks head) Oh, no, another conspiracy possibility. The Orion-1 telescope on Salyut-1 had just been used in 1971 to start looking at the UV sky. Someone in The Conspiracy realized that this would compromise the plausibility of the faked Apollo 16 film which had already been loaded into the camera, and arranged to sabotage the Soyuz 11 pressure-equalization valve, thereby dooming the crew. Even so, useful UV exposures of two sky fields did exist on film recovered from the descent capsule. (I'd like to apologize for that, on the chance that this meme escapes into the wild).

Returning to our universe, it's useful for the UV-sky argument to note that the Apollo 16 pictures were published within a few months of the mission, before the TD-1 satellite had finished mapping all these parts of the sky in the UV. This was also well before Soyuz 13 flew with Orion-2 and observed a lot more of the sky in UV, which was during the final Skylab mission which carried Karl Henize's UV camera as well as a modified version of Carruther's Apollo 16 camera to give independent surveys of the UV sky.

Attached Thumbnails