Mons Rümker lunar dome on the moonThe week of March 8-14 takes us from Lunar Day 25 to Day 2. This week we will highlight Mons Rümker, a complex of domes in the northern part of Oceanus Procellarum early Tuesday morning.

Mons Rümker is an extensive complex of domes on the moonMons Rümker: [NW/E4] Unfortunately this feature is too close to the Moon’s limb to see it very clearly, so coordinate your viewing with a favorable libration (which will be the case Tuesday morning). In spite of its name, Mons Rümker is not really a mountain, it’s an extensive complex of domes. The diameter of the formation is over 40 miles. Although there are about a dozen domes here1, through a telescope it looks like a mound with a bumpy surface. Several of the domes have summit pits. Can you make any of them out?

1 Some sources say 30; how many can you see?


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
Mons Rümker: Lunar Dome on the Moon

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