Difference between revisions of "April 22, 2010"

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=Colorful Pits=
 
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<em>south up image by [mailto:mauricejscollins@hotmail.com Maurice Collins], Palmerston North, New Zealand</em><br />
 
<em>south up image by [mailto:mauricejscollins@hotmail.com Maurice Collins], Palmerston North, New Zealand</em><br />
 
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A few days [/April+18%2C+2010 ago] when I saw Maurice's draping of the old (but only one that exists) USGS geologic map of the Moon over a digital terrain map created with Jim Mosher's LTVT using the LRO laser altimetry data, I realized how helpful combining data sets can be in understanding our satellite. But I noticed that away from the terminator the DTM accurately showed no shadows and hence it was hard to compare geology with topography. I asked Maurice if it would be possible to use LTVT to depict the DTM with a constant Sun angle across the Moon. Jim [http://ltvt.wikispaces.com/Special+Version+-+Constant+Illumination modified] LTVT for Maurice to do that and, presto, we have the lunar nearside geology superposed on a topo map with 2° illumination everywhere. The highlands are very reminiscent of the old [http://atschool.eduweb.co.uk/bookman/library/THEMOON/INDEX.HTM Nasmyth] plaster [http://atschool.eduweb.co.uk/bookman/library/THEMOON/PLATE20.JPG models] that exaggerated the relief of craters. But this is the actual, but impossible, way the Moon would look if everywhere could instantaneously be illuminated with a low Sun. The yellow and green colors indicate the post-mare craters, and clearly they are not evenly distributed across the nearside; the only large ones in the upper-right quadrant are Tycho and Bullialdus. The map also shows two long ridges defined by shadows - they cross just above and to the left of Eudoxus. Are they real or eye-fooling imaginary lines?<br />
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A few days [[April_18,_2010|ago]] when I saw Maurice's draping of the old (but only one that exists) USGS geologic map of the Moon over a digital terrain map created with Jim Mosher's LTVT using the LRO laser altimetry data, I realized how helpful combining data sets can be in understanding our satellite. But I noticed that away from the terminator the DTM accurately showed no shadows and hence it was hard to compare geology with topography. I asked Maurice if it would be possible to use LTVT to depict the DTM with a constant Sun angle across the Moon. Jim [http://ltvt.wikispaces.com/Special+Version+-+Constant+Illumination modified] LTVT for Maurice to do that and, presto, we have the lunar nearside geology superposed on a topo map with 2° illumination everywhere. The highlands are very reminiscent of the old [http://atschool.eduweb.co.uk/bookman/library/THEMOON/INDEX.HTM Nasmyth] plaster [http://atschool.eduweb.co.uk/bookman/library/THEMOON/PLATE20.JPG models] that exaggerated the relief of craters. But this is the actual, but impossible, way the Moon would look if everywhere could instantaneously be illuminated with a low Sun. The yellow and green colors indicate the post-mare craters, and clearly they are not evenly distributed across the nearside; the only large ones in the upper-right quadrant are Tycho and Bullialdus. The map also shows two long ridges defined by shadows - they cross just above and to the left of Eudoxus. Are they real or eye-fooling imaginary lines?<br />
 
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<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br />
 
<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br />
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<div>You can support LPOD when you buy any book from Amazon thru [http://www.lpod.org/?page_id=591 LPOD!]<br />
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===COMMENTS?===
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Register, and click on the <b>Discussion</b> tab at the top of the page.
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<p><b>Yesterday's LPOD:</b> [[April 21, 2010|Every One a Winner]] </p>
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<p><b>Tomorrow's LPOD:</b> [[April 23, 2010|A Lovely Conjunction Between the Moon, with a Colorful Corona, Mars And the Beehive Open Cluster]] </p>
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Latest revision as of 20:52, 8 February 2015

Colorful Pits

LPOD-Apr-22-10.jpg
south up image by Maurice Collins, Palmerston North, New Zealand

A few days ago when I saw Maurice's draping of the old (but only one that exists) USGS geologic map of the Moon over a digital terrain map created with Jim Mosher's LTVT using the LRO laser altimetry data, I realized how helpful combining data sets can be in understanding our satellite. But I noticed that away from the terminator the DTM accurately showed no shadows and hence it was hard to compare geology with topography. I asked Maurice if it would be possible to use LTVT to depict the DTM with a constant Sun angle across the Moon. Jim modified LTVT for Maurice to do that and, presto, we have the lunar nearside geology superposed on a topo map with 2° illumination everywhere. The highlands are very reminiscent of the old Nasmyth plaster models that exaggerated the relief of craters. But this is the actual, but impossible, way the Moon would look if everywhere could instantaneously be illuminated with a low Sun. The yellow and green colors indicate the post-mare craters, and clearly they are not evenly distributed across the nearside; the only large ones in the upper-right quadrant are Tycho and Bullialdus. The map also shows two long ridges defined by shadows - they cross just above and to the left of Eudoxus. Are they real or eye-fooling imaginary lines?

Chuck Wood

Related Links
Maurice's website


Yesterday's LPOD: Every One a Winner

Tomorrow's LPOD: A Lovely Conjunction Between the Moon, with a Colorful Corona, Mars And the Beehive Open Cluster


COMMENTS?

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