Observation by Rik Hill: The Lunar "X"

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Richard "Rik" Hill


Rik Hill


2016 May 14 - 09:17


2018 Nov 09 - 06:32


The Moon

  • 3.5" Questar @ f/24.4 (internal barlow)
  • SKYRIS 445M camera + 656.3 filter

Loudon Observatory, Tucson, Arizona, USA ( long. -110.77639 deg. W lat. +32.18025 deg.)

Target name

An "X" on the moon.


The Lunar "X"

About this image

 In the center of image is the flat bottomed 65km diameter crater Apianus. Just above it is the slightly smaller crater Playfair (49km), half in shadow here. Between them and slightly left (west) is the large 94km basin simply named Playfair G. To the lower left of Playfair are two large shadow filled craters. The lower one is the 82km Aliacensis, and to the upper left from that the 71km Werner. These two craters point right to the "X".

This interesting feature is formed from the walls of Purbach and Blanchinus which are largely in shadow except for the higher parts of their walls. Blanchinus is directly above Werner and Purbach immediately to its left.

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