The week of September 25 – October 1 takes us from Day 5 to Day 11, a very rewarding time to be observing the Moon. This week we will highlight the ghost crater Lamont, visible on Monday night late.
Lamont: [NE/J12] About 100 miles (1.5 arc-minutes) off the western shore of Tranquility is a remarkable series of wrinkle ridges. You need to view them under a low Sun around Day 5 or 6. The terminator should be just touching the western edge of Lamont on Monday around 11:00 PM, but if not enough of the feature is revealed, wait until 3:00 A.M. or try tomorrow night. Lamont is apparently the ghostly remnant of a small multi-ring impact basin that has been covered up by subsequent lava flows, but it doesn’t fit in with the standard sequence of crater morphology. Multi-rings do not generally appear until a crater attains a diameter of around 200 miles. If you catch it at the right time, the image of the underlying basin and rings show up remarkably well on the surface of Tranquillitatis.
OF ADDITIONAL INTEREST IN SPACE FROM SEPTEMBER 25 – OCTOBER 1:
On Tuesday evening, Saturn will be only about 2.75° below the Moon, both of them fitting easily in the same binocular field.
It is highly recommended that you get a copy of Sky and Telescope’s Field Map of the Moon, the very finest Moon map available for use at the telescope. It is available for $10.95 at www.skyandtelescope.com and on Amazon. All features mentioned in this blog will be keyed to the grid on the Field Map and will look like this: Plato: [NW/D9]
Courtesy of Gray Photography of Corpus Christi, Texas
Lunar photos: NASA / USGS / BMDO / LROC / ASU / DLR / LOLA / Moon Globe. Used by permission
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