October 13, 2012

Another Mare

image by Israel Tejera Falcón, Vecindario, Las Palmas, Canary Islands, Spain

Recently, LPOD has been collecting great images of entire maria and surrounding basins. Here is another, the compact basin Humorum, with faults, rilles and volcanics. At top right is a long sinuous rille that disappears soon after passing through two ridges, or pillars, just as they would enter Mare Humorum. Israel's image also beautifully captures the craterful of rilles that is Gassendi. Variants of the floor-fractured crater theme occur at the south end of the mare with Doppelmayer and Vitello - which also has a line of bright dots that look like LEDs signaling to us. My favorite large features of Humorum are the large concentric rilles on the east of the basin. In various basins the mare edges are marked by thin rilles that mark bending fractures from when the center of the basin subsided from the weight of mare lavas. But the Hippalus Rilles are wider than normal and are widely space. Instead of being a bending hinge line there is a 50 km wide zone of bending. My favorite small features of Humorum are the volcanic rilles and fault along the mare's western shore. At the northwest edge you can see where the mare lavas lapped up against older material. Further south the fault cut through a crater and a subsequent crater smashed into the fault. Make sure to look at southwestern Humorum under high Sun illumination too to detect the pyroclastic deposits erupted from the narrow rille.

Chuck Wood

Technical Details
26/9/2012. Celestron CPC XLT 11" + Barlow: Orion x2 + Camera: Lumenera Skynyx 2-0M

Related Links
Rükl plate 52
Israel's website

Yesterday's LPOD: Always Something To See

Tomorrow's LPOD: Tilted Sliver

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