365 Days of the Moon -- August 22, 2014
Janssen, Rima Janssen, and Fabricius
More terminator madness! I have been having fun looking at familiar craters under very low illumination angles. The low sun creates a whole new
personality for an otherwise overly-familiar crater. Here we see Janssen on the southeastern quadrant of the Moon's face. Under higher sun,
shallow Janssen virtually disappears. Though it spans 115 miles, the novice observer often overlooks Janssen because it lacks depth compared to
its width and the crater's rim blends into the surrounding highlands. Most people spot Fabricius, itself almost 50 miles wide, laying in the
upper right corner of Janssen, and think that is Janssen, while overlooking the even bigger crater surrounding Fabricius. The low sun also
accentuates the forked rille, Rima Janssen, within the floor of Janssen.
Image taken through a Celestron 11 Edge HD with a 2.5X Powermate and
Skyris 274M camera.
Image copyright Robert Reeves 2014
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