Janssen and Fabricius

[michaelmorris]

Here is my effort on Janssen (the large eroded crater) and Fabricius (the sharp crater with the prominent central peak) from the night of 1st March. Best 400 frames from 2000 stacked with Avistack, then processed in Photoshop CS2 with Focusmagic plug-in.

[barkis]

Fine result Michael. Is Janssen lava filled or something? You said eroded, in my ignorance I'm thinking of erosion in terms of wind, but on an airless world.? Also, what is the escarpment type structure in Fabricius near the North (as we look) wall.

Ron.

[JCJC]

Great image Michael, really sharp.

Jordan

[michaelmorris]

Is Janssen lava filled or something?

Well spotted. There does certainly appear to be a relatively crater-free area in the bottom left of the crater doesn't there. Apparently there is evidence in the form of a volcanic dome within the crater so resurfacing by lava flow sounds plausible.

You said eroded, in my ignorance I'm thinking of erosion in terms of wind, but on an airless world.?

From my understanding the erosive power on the Moon is micro-meteorite impacts. Over the last 3+ billion years there has been a veritable rain of small dust particales falling on the moon's surface. With no air to slow them down, the little suckers hit at quite a speed. This erosive process is known as 'gardening'. Most of the lunar surface is covered in a soil-like material called regolith that is caused by gardening.

Also, what is the escarpment type structure in Fabricius near the North (as we look) wall.

I agree it looks like an escarpment. However, according the Charles Wood (ex-Nasa lunar geologist I believe) the most likely explanation is that it is were the crater wall and collapse inwards. What we see is the landslide (or should that be moonslide?)

[barkis]

It is certainly a very interesting body our moon. It's incredible how the same features change so much with the angle of the sunlight falling on them. I do enjoy lunar observation, unfortunately I tend to skip from place to place. I'm pretty indisciplined when it comes to the moon. Pretty shabby really, I should know better. I often preach to others about really studying, and not just looking.

Ron.