The week of January 18-24 takes us from Lunar Day 6 to Day 11. This week we will highlight an object informally known as the Valentine Dome.

Valentine Dome on the moonValentine Dome: [NE/F11] Keep a close eye on the movement of the terminator, and when it just touches the western shore of Serenity, which will be the case on Wednesday evening, you will be able to make out a 20-mile wide volcanic dome (the largest dome on the Moon) located in what passes for the Straits of Serenity—the gap in the mountains where Serenitatis seems to flow into Mare Imbrium. This is an unusually large dome that must be caught under a low Sun. Although it does not have an official name, it is popularly referred to as the Valentine Dome because under certain lighting conditions it has a heart shape. Revisit the area several times under different low-sun lighting conditions & see if you can catch the Valentine. Sitting atop the dome are three conspicuous hills (which are Mare Serenitatis on the moonaccompanied by six smaller ones). They are difficult to see but worth a try.


Around 6:30 on Wednesday, Jan. 20, Mars will be 6° from the Moon (about half a fist) and exactly above it. And, a nice treat, Uranus will only be 1°37′ below Mars. Use binocs (if you have wide angle binocs you can catch Mars, Uranus, and 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
Valentine Dome on the Moon

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