The week of August 19-25 takes us from Day 15 to Day 21. This week we will highlight Vallis Rheita, located in the SE quadrant of the Field Map at N14 and viewable on Wednesday night.
Vallis Rheita: [SE/N14; L=52°E] At 276 miles, the Rheita Valley is the longest distinct valley on the Moon. If you look closely at this formation you will see that it is not a valley in the traditional sense but is made up of a series of interlocking craters whose alignment significantly points back to Mare Nectaris, their place of origin. When the Nectaris basin was blasted out 3.9 billion years ago, more than a dozen mountain-sized chunks of debris took flight in a curiously straight line, and when they landed they ploughed out a 240-mi. long trough which we enjoy observing today as the Rheita Valley.
At the northeast end of Rheita Valley, you will find the 45-mi. moon crater for which it was named. It is not difficult to figure out which came first, the moon crater or the valley. See what you think.
Although the Moon usually appears absolutely flat, this sector of the Moon gives you a noticeable three-dimensional effect as Rheita Valley diminishes into the distance around the curve of the Moon.
OF ADDITIONAL INTEREST IN SPACE
On Tuesday, Saturn is 4° south of the Moon.
On Sunday, the Pleiades are 0.1 south of the Moon.
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]
Credits:
Courtesy of Gray Photography of Corpus Christi, Texas
Lunar photos: NASA / USGS / BMDO / LROC / ASU / DLR / LOLA / Moon Globe. Used by permission
- Moon Crater Maurolycus in the Lunar Highlands - September 9, 2024
- Mare Nectaris – Multi-Ring Basin on the Moon - September 2, 2024
- Lunar Swirl Reiner Gamma and the Struve/Russel Moon Crater - August 26, 2024