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| =Tiny Peaks= | | =Tiny Peaks= |
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| <em>images from Clementine at USGS [http://pdsmaps.wr.usgs.gov/PDS/public/explorer/html/moonpick.htm Map-A-Planet]</em></p> | | <em>images from Clementine at USGS [http://pdsmaps.wr.usgs.gov/PDS/public/explorer/html/moonpick.htm Map-A-Planet]</em></p> |
| <p>My first scientific paper was on central peaks of lunar craters, and I haven’t lost my fascination with them yet. Studies of terrestrial impact craters demonstrate that central peaks are rebounds of deep target rocks. Rocks from a depth beneath the surface of roughly 1/10th a crater’s diameter are exposed in peaks. Thus, the central mountains on the floor of 93 km wide Copernicus are thought to come from about 6-10 km below the surface. When I originally studied peaks I used photographs from Kuiper’s 1960 <em>Photographic Lunar Atlas</em>. I discovered that peaks are rare in craters smaller than 10-15 km in diameter and become progressively more common in larger craters. I repeated this [http://articles.adsabs.harvard.edu//full/1978LPSC....9.3669W/000<br /> | | <p>My first scientific paper was on central peaks of lunar craters, and I haven’t lost my fascination with them yet. Studies of terrestrial impact craters demonstrate that central peaks are rebounds of deep target rocks. Rocks from a depth beneath the surface of roughly 1/10th a crater’s diameter are exposed in peaks. Thus, the central mountains on the floor of 93 km wide Copernicus are thought to come from about 6-10 km below the surface. When I originally studied peaks I used photographs from Kuiper’s 1960 <em>Photographic Lunar Atlas</em>. I discovered that peaks are rare in craters smaller than 10-15 km in diameter and become progressively more common in larger craters. I repeated this [http://articles.adsabs.harvard.edu//full/1978LPSC....9.3669W/000<br /> |
− | 3669.000.html study] in 1978 using Lunar Orbiter images and found that nearly all fresh craters larger than 35 km have central peaks but fewer than 4% of craters smaller than 5 km have peaks. The newer Clementine data with the high Sun imaging of much of the Moon suggests that central peaks may be more common in small craters than I thought in 1968 and in 1978. The 15 km wide farside crater [http://the-moon.wikispaces.com/Glauber Glauber] has a perfect bright dot of a peak on its flat floor. So does the like-sized [http://the-moon.wikispaces.com/Dunthorne Dunthorne], and the floor of 17 km wide [http://the-moon.wikispaces.com/Maury Maury] is crowded with five rounded hills. At a crater diameter of 15 km, peaks are not completely rare but are less uncommon than I thought. The USGS Map-A-Planet site has been down the last couple of days so I can’t check Clementine, but it will be worthwhile to look for peaks in smaller craters. </p> | + | 3669.000.html study] in 1978 using Lunar Orbiter images and found that nearly all fresh craters larger than 35 km have central peaks but fewer than 4% of craters smaller than 5 km have peaks. The newer Clementine data with the high Sun imaging of much of the Moon suggests that central peaks may be more common in small craters than I thought in 1968 and in 1978. The 15 km wide farside crater [https://the-moon.us/wiki/Glauber Glauber] has a perfect bright dot of a peak on its flat floor. So does the like-sized [https://the-moon.us/wiki/Dunthorne Dunthorne], and the floor of 17 km wide [https://the-moon.us/wiki/Maury Maury] is crowded with five rounded hills. At a crater diameter of 15 km, peaks are not completely rare but are less uncommon than I thought. The USGS Map-A-Planet site has been down the last couple of days so I can’t check Clementine, but it will be worthwhile to look for peaks in smaller craters. </p> |
| <p>[mailto:tychocrater@yahoo.com Chuck Wood]</p> | | <p>[mailto:tychocrater@yahoo.com Chuck Wood]</p> |
| <p><strong>Related Links:</strong><br /> | | <p><strong>Related Links:</strong><br /> |
| My original article on central peaks was in the Communications of the Lunar and Planetary Lab and is not on line. </p> | | My original article on central peaks was in the Communications of the Lunar and Planetary Lab and is not on line. </p> |
− | <p align="center"> | + | <p><b>Yesterday's LPOD:</b> [[August 21, 2007|Tributaries?]] </p> |
− | <i>You support [http://www.lpod.org/?page_id=591 LPOD] when buying lunar books (or ANY book) from Amazon!</i></p> | + | <p><b>Tomorrow's LPOD:</b> [[August 23, 2007|Striking Slips]] </p> |
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