365 Days of the Moon -- August 19, 2014

Mare Vaporum, Sinus Medii, and the Moon's central rilles


Is the Moon all it's cracked up to be? It is if you look in the right places. In the center of the Moon's disk we see the dark patches of Mare Vaporum (Sea of Vapors) and Sinus Medii (Middle Bay). These dark areas make the Man-in-the-Moon's nose. This region is rich in large rilles, or cracks in the surface of the Moon. At the right we see the lengthy straight Ariadeaus Rille. This crack is actually a graben, a feature caused by the slumping of land between two parallel faults. To the left of Ariadaeus is the gull wing-shaped volcanic Hyginus Rille. Both "wings" branch off small Hyginus crater in the middle. But this is not an impact crater. Hyginus is actually a volcanic collapse pit. Below Hyginus is the network of Triesnecker Rilles. The Triesneckers are known as "irregular branching" rilles because they fork all over the place, through you can't see some of them in this high-altitude shot.

Notice the rough dark patch of volcanic deposits just above the Hyginus Rille. To my imagination, this looks like a heart. Look closely....can you see the rough area as the shape of a Valentine heart? I can, and thus I call this feature the "Heart of the Moon".

Image taken with a Celestron 11 Edge HD and a Skyris 274M camera.

Image and content Copyright Robert Reeves 2014


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