Difference between revisions of "August 5, 2012"
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<em>Color image from Clementine, and monochrome ones from LRO, with processing by Maurice Collins (center) and LRO team (right).</em><br /> | <em>Color image from Clementine, and monochrome ones from LRO, with processing by Maurice Collins (center) and LRO team (right).</em><br /> | ||
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| − | As soon as I looked at a high Sun mosaic of LRO Wide Angle Camera images of the southeastern edge of Mare Serenitatis that Maurice Collins | + | As soon as I looked at a high Sun mosaic of LRO Wide Angle Camera images of the southeastern edge of Mare Serenitatis that Maurice Collins |
| − | had constructed I was struck by a what appeared to be an oblique impact crater north of the Apollo 17 region. With enlargement and a closer look | + | had constructed I was struck by a what appeared to be an oblique impact crater north of the Apollo 17 region. With enlargement and a closer look |
| − | it appears like a horizontal linear chain with rays radiating from the entire 10 km length (middle image). If this were Earth I would assume that the | + | it appears like a horizontal linear chain with rays radiating from the entire 10 km length (middle image). If this were Earth I would assume that the |
| − | chain was a volcanic fracture and the light material was ash ejected from it. But on the Moon bright material is almost always ejecta from impact | + | chain was a volcanic fracture and the light material was ash ejected from it. But on the Moon bright material is almost always ejecta from impact |
| − | craters - was this a fresh crater chain with rays from each crater? The right image, from the lower Sun LRO QuickMap, suggests that only the crater | + | craters - was this a fresh crater chain with rays from each crater? The right image, from the lower Sun LRO QuickMap, suggests that only the crater |
| − | sometimes known as Littrow BA is likely to be young enough to be a ray crater. But if this line of craters - formally known as the Littrow Chain - is | + | sometimes known as Littrow BA is likely to be young enough to be a ray crater. But if this line of craters - formally known as the Littrow Chain - is |
| − | a secondary chain or even more exotically a chain from a sheared comet or asteroid, all parts would have formed nearly at the same instant. The | + | a secondary chain or even more exotically a chain from a sheared comet or asteroid, all parts would have formed nearly at the same instant. The |
| − | NAC images of KA reveal a small pond of impact melt on its floor, so the crater is younger than its rim implies. The Clementine color composite (left) | + | NAC images of KA reveal a small pond of impact melt on its floor, so the crater is younger than its rim implies. The Clementine color composite (left) |
| − | shows that the bright material is compositionally different - it is orange - compared to the bright nimbus (red) around Clerke and older volcanics on | + | shows that the bright material is compositionally different - it is orange - compared to the bright nimbus (red) around Clerke and older volcanics on |
| − | the right. Based on these images it seems that the components of the chain formed at about the same time, each crater ejecting its own rays. It was | + | the right. Based on these images it seems that the components of the chain formed at about the same time, each crater ejecting its own rays. It was |
| − | an oblique impact, accounting for the zones of avoidance at both the left and right ends. Two things are unusual: it is a crater chain with rays, and a | + | an oblique impact, accounting for the zones of avoidance at both the left and right ends. Two things are unusual: it is a crater chain with rays, and a |
| − | young feature with irregular rims and an old morphology. <br /> | + | young feature with irregular rims and an old morphology. |
| + | <br /> | ||
<br /> | <br /> | ||
<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br /> | <em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br /> | ||
<br /> | <br /> | ||
<strong>Related Links</strong><br /> | <strong>Related Links</strong><br /> | ||
| − | Rükl plate [ | + | Rükl plate [https://the-moon.us/wiki/R%C3%BCkl_25 25]<br /> |
<br /> | <br /> | ||
| + | <p><b>Yesterday's LPOD:</b> [[August 4, 2012|Rim Ash?]] </p> | ||
| + | <p><b>Tomorrow's LPOD:</b> [[August 7, 2012|Intersections]] </p> | ||
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Latest revision as of 18:44, 13 October 2018
Secondary Rays
Color image from Clementine, and monochrome ones from LRO, with processing by Maurice Collins (center) and LRO team (right).
As soon as I looked at a high Sun mosaic of LRO Wide Angle Camera images of the southeastern edge of Mare Serenitatis that Maurice Collins
had constructed I was struck by a what appeared to be an oblique impact crater north of the Apollo 17 region. With enlargement and a closer look
it appears like a horizontal linear chain with rays radiating from the entire 10 km length (middle image). If this were Earth I would assume that the
chain was a volcanic fracture and the light material was ash ejected from it. But on the Moon bright material is almost always ejecta from impact
craters - was this a fresh crater chain with rays from each crater? The right image, from the lower Sun LRO QuickMap, suggests that only the crater
sometimes known as Littrow BA is likely to be young enough to be a ray crater. But if this line of craters - formally known as the Littrow Chain - is
a secondary chain or even more exotically a chain from a sheared comet or asteroid, all parts would have formed nearly at the same instant. The
NAC images of KA reveal a small pond of impact melt on its floor, so the crater is younger than its rim implies. The Clementine color composite (left)
shows that the bright material is compositionally different - it is orange - compared to the bright nimbus (red) around Clerke and older volcanics on
the right. Based on these images it seems that the components of the chain formed at about the same time, each crater ejecting its own rays. It was
an oblique impact, accounting for the zones of avoidance at both the left and right ends. Two things are unusual: it is a crater chain with rays, and a
young feature with irregular rims and an old morphology.
Chuck Wood
Related Links
Rükl plate 25
Yesterday's LPOD: Rim Ash?
Tomorrow's LPOD: Intersections
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