The week of October 24 – 30 takes us from Lunar Day 29 to Day 6. This week we will highlight:

Arago unusual crater on moonArago: [NE/J12; L=21°E] About 50 miles from the western shore of Tranquillity you will find the crater Arago (16 mi.). This is an unusual crater. In the place of a central peak you will see a substantial ridge that extends from the center of Arago’s floor to its northern rim. The evidence suggests that there was a significant collapse of rim material which simply merged with the central peak.

Arago Domes on the moonArago Domes: [NE/J12; L=21°E] On Day 4 you may have seen your first lunar domes around the crater Cauchy. Now you can broaden on the experience. Arago has a pair of very large domes, one to its north (Arago a [Alpha]) and one to its west (Arago b [Beta]). These are two of the largest and most prominent domes on the Moon, and halfway between Arago  and the crater Maclear (100 miles to its northeast) you will find a challenging group of four smaller domes. It will be a nice victory for you if you manage to spot them.


On Friday the Moon will be at perigee (it’s closest distance from the Earth during the lunar month), so it will appear slightly larger.


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 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

Andrew Planck
Arago: Unusual Moon Crater and Pair of Large Domes

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