LROC news and images |
LROC news and images |
Mar 26 2012, 02:40 PM
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#436
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Member Group: Members Posts: 696 Joined: 3-December 04 From: Boulder, Colorado, USA Member No.: 117 |
Sorry I missed your talk at LPSC, Phil, but I just checked out your abstract. Nice work! These hollows are fascinating. There seems to be a difference from the Mercury hollows, because those on Mercury are exclusively associated with impact craters, while the Moon ones are often associated with volcanic areas instead. Do you agree? I liked the suggestion at LPSC by Vaughan that the Mercury hollows were due to sublimation of some volatile "scum" that floated to the top of impact melt sheets, but I'm not sure how to apply that idea to lunar volcanic features.
John |
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Mar 26 2012, 02:41 PM
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#437
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
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Mar 26 2012, 03:59 PM
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#438
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Member Group: Members Posts: 909 Joined: 4-September 06 From: Boston Member No.: 1102 |
They looked like plateaus to me until I looked at another image M142570512. On second thought, I am having trouble visualizing them again. Are these plateaus or indentations? It's the lighting! We are used to light coming from above in a scene. Print out the picture and flip upside down. --Well worked fine for me for one look, but turned it and now can't get my mid to let go of plateaus regardless of angle--darn visual cortex is not under voluntary control. [edit] Put the picture on my wall and went for a 20 minute walk. Brain processed image correcty when I returned.. -------------------- |
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Mar 26 2012, 07:25 PM
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#439
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
They are depressions, for sure.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Mar 26 2012, 07:40 PM
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#440
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Senior Member Group: Members Posts: 1578 Joined: 14-October 05 From: Vermont Member No.: 530 |
Would be a fun shape-from-shading image. Pretty neat.
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Mar 26 2012, 08:22 PM
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#441
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
John - I agree about the difference between Mercury and Moon hollows... though some Mercury hollows are up on the central peaks or peak rings of craters and basins, and I'm not sure if that works with the impact melt idea. Hyginus and Sosigines craters contain hollows, but none other that I've found yet.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Mar 26 2012, 08:27 PM
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#442
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
QUOTE They looked like plateaus to me A standard optical illusion light from the upper left corner or from the lower left can invert the way the brain "sees" it |
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Mar 26 2012, 08:54 PM
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#443
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
The cure: Arrange for the lighting in your room to be from the same direction as the lighting in the image. Conscious control over the visual cortex is thereby reasserted.
(Sorry - I've posted this before but I couldn't find where.) |
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Mar 27 2012, 12:23 AM
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#444
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Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
The voids remind me of what you see when a viscous liquid tries to flow across a rough surface, like paint on concrete or water spilling across hard-packed dirt. I'm not proposing that an analog process is occurring, just pointing out that's what it looks like -- particularly the boundaries inside the hollows the way they sort of curve downward and appear to pull back.
-------------------- If Occam had heard my theory, things would be very different now.
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Mar 27 2012, 04:05 AM
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#445
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
The out gassing reminds me of what salt looks like on the concrete after the ice/water has evaporated
I live in the NORTH so ....(N 42.38841 ) |
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Apr 24 2012, 02:14 PM
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#446
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
Nice new pic from LRO for the Apollo 16 anniversary. Here's Shadow Rock (Station 13) above left of centre with footprints around it, and LRV tracks at lower right.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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May 5 2012, 04:21 AM
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#447
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
I have added the Apollo 16 traverse map (at the LPI website) to the above map to show how accurate it was. The plotted Station 13 was about 50 m off its real location.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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May 5 2012, 06:20 PM
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#448
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Junior Member Group: Members Posts: 52 Joined: 1-March 11 From: Houston, USA Member No.: 5860 |
...Are these plateaus or indentations? The craters around them indicate indentations, but then the mind wants them to be plateaus.... They look more like hollows/indentations in the inverted image -- I think the bright regolith-free(?) surfaces in the original image make them look like plateaus. I can almost convince myself of subtle raised aprons around the hollows, as if the regolith were removed upward and outward. Imaging these hollows at different sun angles might be...illuminating. |
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May 8 2012, 01:50 PM
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#449
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Junior Member Group: Members Posts: 62 Joined: 30-July 09 Member No.: 4887 |
Apollo Lunar Surface Journal on Apollo Flags as seen by LRO.
Hope you don't mind tooting my own horn, but I am pleased to be able to post something in the "nasa.gov" domain (it wasn't easy) on something I hope some people find of interest. See following link: Apollo Lunar Surface Journal Apollo Flags Link |
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May 8 2012, 02:03 PM
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#450
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Solar System Cartographer Group: Members Posts: 10128 Joined: 5-April 05 From: Canada Member No.: 227 |
Toot away James, this is great.
But I would take issue with you on one point. At Apollo 15 you say there is no clear evidence of a flag shadow, and that is true in the first frames, but not in the last three where a very dark shadow appears and moves as expected. Maybe the orientation of the flag is such that the early frames are casting a very thin shadow (i.e. the sun is in the plane of the flag in the mid-morning). Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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