Lunar Spacecraft Images, A place for moon panoramas, mosaics etc. Options

[AndyG]

Depending on the orientation of the panel (just one, the other is an aerial) I suspect that at either sunrise or sunset you might get an Iridium-like flare from the surface. Iridium panels must be about three or four times the surface area, however, and are a quarter of a million miles closer to us - but they *do* reach minus magnitudes!

They do: I see it's about mag -8 at the maximum.

But that distance is killer #1: an iridium flare at lunar distances, compared to the 780km orbit of the satellite, will be about one quarter million times dimmer. Killer #2 is the size and finish of the panels - they're not polished metal as with the Iridium satellites, they're designed specifically as light-absorbing materials. Being generous, let's say they're ten times dimmer. Killer #3 is that they are (as you state) three to four times smaller. So we're dealing with a transient flash perhaps ten million times dimmer than mag -8, which is equal in magnitude to +9.5. Not bright - especially against a lunar background.

The final nail in the coffin, as I see it, is that the angle of the panels are not known with any great precision. At the Moon's distance the Earth only subtends 2 degrees. Iridium flares on the Earth are very localised: just a few miles can take you from a "wow" flare to a "ok, so I saw it" one - I can see that it would be extremely likely for any equivalent lunar flares to miss the Earth completely, for all (or a huge amount) of the time.

Shame though. :-)

Andy

[Bob Shaw]

Andy and Phil:

I take your points - but remember the famous Mars flashes, from about 150 times further away?

It may well be that nothing is visible, but it's worth a little thought - it'd be great if something *was* seen!

If the Surveyor solar panels (not counting the failures, which are probably debris) were arranged to face the morning or evening sun (depending on when the vehicles turned off) then I wonder whether there might be glints visible from Lunar orbit? One problem might be predicting where the darn things are pointing - as I'm sure you know, Surveyor 3 woke up enough to try to take TV pictures *after* it lost contact with Earth (the vidicon tube was damaged by UV as a result of a filter opening, although it was closed when the spacecraft was last in touch with the ground, so it must have decided to do it all by itself!) so perhaps the solar panels are at some utterly unknown angle!

Bob Shaw

[dvandorn]

Andy and Phil:

I take your points - but remember the famous Mars flashes, from about 150 times further away?

Ahh, but I have it from reliable sources that a Professor Pearson from Princeton University has identified those Mars flashes as vast explosions of hydrogen gas. While these may seem unusual, they are more than likely simply the result of volcanic activity, and shouldn't concern us in any way...



-the other Doug

[edstrick]

Nah..... not hydrogen.

Methane!

[Phil Stooke]

"Surveyor 3 woke up enough to try to take TV pictures *after* it lost contact with Earth (the vidicon tube was damaged by UV as a result of a filter opening, although it was closed when the spacecraft was last in touch with the ground, so it must have decided to do it all by itself!) so perhaps the solar panels are at some utterly unknown angle!

Bob Shaw"


Yes, Bob, but Apollo 12 photos show us the orientation now.

Phil

[ljk4-1]

"Surveyor 3 woke up enough to try to take TV pictures *after* it lost contact with Earth (the vidicon tube was damaged by UV as a result of a filter opening, although it was closed when the spacecraft was last in touch with the ground, so it must have decided to do it all by itself!) so perhaps the solar panels are at some utterly unknown angle!

Bob Shaw"
Yes, Bob, but Apollo 12 photos show us the orientation now.

Phil

I was told in this forum that the Surveyors did not have
the computer capacity to do many things on their own.

Was this one of those exceptions?

Makes one wonder if any of the other Surveyors also
tried to do one last task before expiring?

Until we can actually get an exoarchaeological team there
to study these old probes, can the LRO determine anything,
such as an unpredicted orientation, or will we just be lucky
enough to even see them on the lunar surface?

[Bob Shaw]

"Surveyor 3 woke up enough to try to take TV pictures *after* it lost contact with Earth (the vidicon tube was damaged by UV as a result of a filter opening, although it was closed when the spacecraft was last in touch with the ground, so it must have decided to do it all by itself!) so perhaps the solar panels are at some utterly unknown angle!

Bob Shaw"
Yes, Bob, but Apollo 12 photos show us the orientation now.

Phil

Phil:

Of course! I was describing the matter of the Surveyor solar panels in general, hence the plural 'panels'. The Apollo 12 panel is the only one where utterly accurate predictions could be made, other than best guesses...

I was told in this forum that the Surveyors did not have
the computer capacity to do many things on their own.

Was this one of those exceptions?

Makes one wonder if any of the other Surveyors also
tried to do one last task before expiring?

Until we can actually get an exoarchaeological team there
to study these old probes, can the LRO determine anything,
such as an unpredicted orientation, or will we just be lucky
enough to even see them on the lunar surface?

I think it wasn't so much a commanded action by a lonely old computer so much as a twitch from a half-broken component or two, aided by a still-working solar panel.

The Sojourner story, that's another matter - it may have trundled around for a while after Pathfinder ceased to operate, bravely crying for it's parent! Maybe MRO will have a cPROTO mode developed which will resolve the little guy's position...

Bob Shaw

[Phil Stooke]

A rather bland image... it's the foreground of the Surveyor 6 post-hop panorama I'm working on. This extends to the right of the previous section. The footpad with its colour disk is at right bottom, with a big patch of disturbed soil. At left are dark streaks made by the thruster firing. A circular pit near the top is an imprint of a shock-absorber, and a pit half-seen at the top edge is a footpad imprint from the imitial landing.

Phil

[tedstryk]

Phil, admit it. You don't reprocess these images. You sneek up there in your "Apollo-B" module, slip your camera next to the Surveyor camera, and snap the pictures. The only editing is to remove your footprints!

Seriously, tremendous work!

[Phil Stooke]

You got it, Ted. The best part is, NASA is paying me $145 billion for the use of my spacecraft in 'the Vision', so now I can pay off my credit card.

Phil

[Phil Stooke]

This is the current state of the Surveyor 6 pan... the original is 11000 pixels long.

Can you tell which part is cleaned up and which I still have to do?

I'm working along the horizon in the middle right now.

Phil

[dilo]

Amazing masterpiece, Phil ... I admire your patience! (what about your Mars atlas project?)

[Bob Shaw]

Phil:

If you ever have time, would you consider talking through some of the processes you use? It'd be instructive to see how your work in progress actually takes place!

Bob Shaw

[Guest_Myran_*]

On the subject on the flashes some claimed to have observed on the Moon and Mars I always have thought those were phosphene flashes in the eyes of the visual observers due to darkness and the late hours they worked.
I think so especially since the few searches with photographic means yielded nothing, even when images were taken simultanously to a claim of a tranisent light, nothing could be seen on the plates.

[Bob Shaw]

On the subject on the flashes some claimed to have observed on the Moon and Mars I always have thought those were phosphene flashes in the eyes of the visual observers due to darkness and the late hours they worked.
I think so especially since the few searches with photographic means yielded nothing, even when images were taken simultanously to a claim of a tranisent light, nothing could be seen on the plates.

Well, the problem with flashes and old-style photography was that the exposures were just too darn long, and the flashes way too short - but recently there *have* been observation made with video cameras showing meteor impacts on the Moon during well-known meteor showers.

There was an article in S&T a few years back which had some interesting arguments for the reality of the Mars flashes, too...

Bob Shaw