The week of February 20-26 takes us from Lunar Day 1 to Day 7. This week we will highlight Rima Ariadaeus, located in the NE quadrant of the Field Map and viewable on Sunday night.

Rima AriadaeusAriadaeus: [NE/J11; L=17°E] The Ariadaeus Rille (Rima Ariadaeus) is named after a 7 mile moon crater located near its eastern end. Notice that the moon crater has a slightly smaller companion touching it on its northeast side. Their rims are gently pushing in on each other. Can you tell which one is older?


On February 22, Venus will be 2° north of the Moon.


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
Rima Ariadaeus – Ariadaeus Rille

Leave a Reply

Your email address will not be published. Required fields are marked *