Pyroclastic Deposits around Copernicus

[astroavani]

Copernicus H (about 4.4 km in diameter, 6.88 ° N latitude, longitude 341.71 ° E), is a crater Copernicus satellite, is located 56 km southeast of Copernicus (crater diameter of 93 km located in eastern Oceanus Procellarum). The bottom image highlights a part of the rim of the crater Copernicus H (see blue square in the image below). Materials of low reflectance extend from the edge and follow down the slope into the crater. What is the origin of these dark materials? Was originated by the impact melt? Are pyroclastic deposits? 

As can be seen in the NAC (below) and my (above), the ejecta of Copernicus H shows relatively lower reflectance than the surrounding area. Normally the material ejected from the crater has a higher reflectance because the material is newly exposed and "immature". Note that the crater floor is largely filled by lower reflectance material, and the materials of high reflectance extend radially from the floor to the crater rim. These materials are bright wreckage on the slope of the crater that descend by gravity toward the center of the crater wall. 

Looking at my picture above context, it is likely that Copernicus H has excavated some underlying materials of low reflectance ejection of Copernicus. Several craters located at least 45 km away from the rim Copernicus also show similar expelled matter. Therefore, the underlying dark material should be widely distributed. What can these materials? 

Pyroclastic deposits in Southern Sinus Aestuum which is located about 90 km southeast of Copernicus H, underlie Copernicus ejection. If this layer is widely distributed in the ejecta of Copernicus, subsequent impacts with sufficient energy could have excavated dark material. 

To unravel these relationships stratigraphic several probes in orbit, collect accurate to have an understanding of the effects of spectral data. New measures LRO, Selene, and Chandrayaan lunar scientists are providing the necessary information! 

Source: LROC / NASA 

Adaptation: Avani Soares 

http://www.astrobin.com/full/116997/0/

[michael.h.f.wilkinson]

Those imaes are awesome!

[Mr Spock]

I think it's likely the dark layer is relatively thin and Copernicus has pulled out lighter material from beneath. This would explain the light coloured ejecta overlaying the darker material. The smaller craters have been formed through the ejecta, revealing the darker 'top layer' and spreading this as ejecta.

The darker material is probably mare lava flow material - it would be interesting to have samples of this material to see how it was formed. On Earth we'd probably be looking at slow flowing pahoehoe type lava, but with the moon's one sixth gravity who knows.

It's an interesting subject and illustrated well by the images. It's another reason why we need to go back to the moon.

[nightfisher]

Avani, yet another superb image, you might be our top Lunar imager

[Baffa]

Wow! This is great!