On Feb 22, 3:50 am, Johan Lundström wrote:
Hello!

I´m trying to find out what the black material is that can be seen
in the bottom om the moons craters.
Annyone have an idea??
Best wishes / Johan

Johan,

Pardon me for not picking up on your question sooner.
If it's not shadows your'e seeing then it's most certainly
ashfalls. Atlas contains some explosive (but inactive)
lava pits and can be found a few degrees East of the
Lacus Mortis. The Mare Humorum is also a crater (large)
and exhibits a pronounced ashfall on the southwest side.
Atlas should be in good observation position on Mar 8.
It also contains some rille structure which accents
its floor with some slender dark shadows.
Sometimes dark, titanium rich lavas can be seen
pooled up on the floors of larger craters but they are
easier to see on the Maria floors. Check the dark band that
separates Tranquility and Serenity. Its a dark blue color
and one can see how the magma flowed out of Serenity
onto Tranquility.

Ben,
90.126 n35.539