A Field Guide To Lunar “Black Stuff”

This week forum regular kodemunkey has chosen to highlight the lunar “black stuff” we have been looking for since Dr Tony Cook asked us to post examples.  Often difficult to distinguish from shadows this black deposit might be volcanic in origin or just a dark albedo feature. Whatever it is we now have quite a collection to study.  Over to kodemunkey to explain further.

Hello once again moon fans, this week I have a strange one for you, Lunar “Black Stuff.”

Of all the sub-topics on the forum, I think this one is the most mysterious and it’s certainly caught my attention.

To quote Anthony Cook on the subject:

“Description: Dark slightly branching features, often on the shaded side of slopes. Boulders associated with these. Also appears as an exposed strata layer in a nearby rill rim.

Interest: Is this “dark stuff” an exposed dark material black volcanic glass, a deep branching crack with shadow, dark boulders, or a combination? Either way we need to find more of these and their geographical distribution. Could be worth monitoring these from orbit and at different sun angles to see if the darkness is related to shadow.”

I, like many people, enjoy both a good mystery and a chance to be nosey, so this was one project that suited me down to the ground (or regolith if you prefer!)

(Obsidian)

Where has it been found so far?

During my time on the forum, I’ve found examples of “Black stuff” in the following locations:

Marius Hills (Perhaps ejecta from Aristarchus / Kepler?)

Schroter, Fauth, Bode, Sommering and Gambart (Ejecta from Copernicus perhaps?)

Vallis Alpes.

As well as various dark haloed craters and other unnamed crater ejecta blankets.

This section is a guide to where you might find examples of Black stuff:

On the edges of rille systems

Vallis Alpes Rille

Rimae Marius

On crater rims

Unamed impact, Taurus-Littrow region

Crater floors

Unnamed far side impact

Occasionally in the ejecta blankets of small impacts

Minor impact within Michelson crater on the far side.

Unnamed near side impact

Covering the landscape

Marius Region

Schroter Region

Question time:
Taking into account the number of impacts, both large and small, why isn’t there more black stuff laying around, and why is it seemingly more prevalent on the near side more than the far side?

Sources used:

WMS Browser: http://wms.lroc.asu.edu/lroc#damoon
Act – React tool: http://target.lroc.asu.edu/da/qmap.html
Moon Zoo Thread “TLP – Black Stuff”: http://forum.moonzoo.org/index.php?topic=264.0
Special mentions go to forum moderators Jules, Geoff, Ireneant and forum members Astrostu and Tom128, who i imagine i drove to insanity badgering them with my own inane ramblings on the subject.