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Post by nomuse on Nov 30, 2007 5:20:57 GMT -4
history.nasa.gov/alsj/a12/AS12-46-6728.jpgLooks a lot like a pit right under the descent engine. From other pictures on that same roll I see what looks more like a shallow but well-defined depression, perhaps a third as deep as it is wide and of roughly conical shape.
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Post by nomuse on Nov 30, 2007 5:28:00 GMT -4
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reynoldbot
Jupiter
A paper-white mask of evil.
Posts: 790
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Post by reynoldbot on Dec 2, 2007 8:20:23 GMT -4
It looks like lighting really determines whether that area looks like a big hole or a small pit. Very interesting.
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Post by nomuse on Dec 2, 2007 15:47:05 GMT -4
Yah.
I left my original late-in-the-AM post as an instructive lesson; that any of us can fall into the trap of seeing something in an image that isn't really there.
True photo analysis is best left to those trained in it.
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Post by Ginnie on Dec 2, 2007 17:28:19 GMT -4
history.nasa.gov/alsj/a12/AS12-46-6728.jpgLooks a lot like a pit right under the descent engine. From other pictures on that same roll I see what looks more like a shallow but well-defined depression, perhaps a third as deep as it is wide and of roughly conical shape. I don't know about my eyes, but is that a coloured refection in the 'pit'. Shows how reflective the moon surface can be? |
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reynoldbot
Jupiter
A paper-white mask of evil.
Posts: 790
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Post by reynoldbot on Dec 2, 2007 21:41:39 GMT -4
history.nasa.gov/alsj/a12/AS12-46-6728.jpgLooks a lot like a pit right under the descent engine. From other pictures on that same roll I see what looks more like a shallow but well-defined depression, perhaps a third as deep as it is wide and of roughly conical shape. I don't know about my eyes, but is that a coloured refection in the 'pit'. Shows how reflective the moon surface can be? It certainly would appear so. |
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Post by JayUtah on Dec 3, 2007 10:58:16 GMT -4
Your second photo is shot with a small phase angle. Lighting will hide contour in that case. The first shot employs a substantial, contour-revealing phase angle.
The "colored reflection" in the feature in question is a caustic reflection of sunlight into the pit from the back side of the MESA wrapper.
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Post by nomuse on Dec 3, 2007 16:25:59 GMT -4
I DID figure the last!
But it was very clear that without tools and the skill to use them, I could not take any of these pictures and determine just how deep the "hole" was -- or even if it was a random crater that just happened to be lined up with the other elements in that particular shot.
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Post by Kiwi on Dec 4, 2007 7:20:50 GMT -4
An interesting impression I get from AS12-46-6728 is that two or three paces beyond the far footpad is a steep "wall" about a metre high, but in reality it could be quite distant, many times higher, and the rocks and craters on it could be very big.
This is the sort of thing that HBs and HPs often insist on -- David Percy does it with the Taurus-Littrow mountains, and others have claimed that Stone Mountain was much closer to the Apollo 16 lunar module than it actually was. Even being there and having binocular vision, the astronauts also had trouble working out sizes and distances.
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Post by PhantomWolf on Dec 4, 2007 16:02:02 GMT -4
The classic of that is the stroll to House Rock, which the astronauts thought was only about 100m away and turned out to be closer to 300m. This little jaunt brought up the witty comment from the control floor of something like, "And as our brave adventurers disappear into the sunset" due to the time it was taking them to get to that "little" rock just over there.
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