Apollo 11 land site area - revisited

With the 45^th anniversary of the Apollo 11 landing coming up, I thought I’d post my sketch of the landing site area for some revision of my original thoughts on some formations.

I used to think that these fissures formed as a result of shrinkage.  This was as a result of my confusing the tiny appearance of these riles through the eyepiece to cooling shrinkage.  But these riles can be over 10km wide, and lava does not shrink this much!  I’m now thinking that these fractures formed when the Moon’s crust was very thin and experienced a massive impact.  The thin crust then would fracture, and in some instances, like the impact site itself, fill with lava, like Rile Hypatia.  Another recent sketch of mine shows a series of co-centric fractures – these are more likely also to be the crazing pattern due to a big impact, not shrinkage.  Examination of the area round Rimae Hippalus makes the likely impact that formed these fractures as being the one that formed the flooded area of Mare Humorum.  Looks like I’ve changed my thinking on how these riles form!

One part of science is to be flexible in accepting new ideas when older ones have been disproved or shown to be mistaken.  Likewise, old ideas also need to be challenged to double check their voracity.  Here is one case where my original think was incorrect, and I've come to a new conclusion following new evidence and correction of original observations.

Object: Apollo 11 landing site area

Scope: C8, 8” SCT

Gear: 8mm LVW, 250X & 5mm Hyperion, 400X

Date: 3rd July, 2014

Location: Sydney, Australia

Media: White and grey soft pastel, charcoal & white ink on A5 size black paper.

Duration: 2hrs.

Alexander Massey.