Hesiodus and Hesiodus A

[Mike JW]

Hesiodus lies next to Crater Pitatus. It lacks a central peak but in the centre is a small impact crater. Its walls are quite worn down with two ghost craters to the north. Rima Hesiodus is a subtle feature and runs SW.  The sketch below was completed awhile back.

Hesiodus A impacts on the wall. - bottom of sketch. It is one of the 58 craters with concentric rings. Such craters are likely to be due to lava welling up through fissures or cracks in the craters' floors. Exactly why the lava in concentric craters bubbled up to form donut-like rings remains unclear. A plug of molten rock beneath the crater may have lifted up its floor, which later deflated in the centre like a collapsed soufflé, leaving a ring. It's even possible that dense impact melt on the crater floor resisted uplift from lava pushing up from below. Whatever the specific reason, most lunar experts agree that concentric craters owe their formation to volcanic processes. Some folk have suggested it is a double impact but it looks too neat and tidy for that to be the case, in my view.

Below is my sketch from last night when conditions were right for high power (x330)  and also the illumination.

[acr_astro]

Hello Mike,

thanks for sharing both the old and the new sketch with us here. Both are great!

Clear skies!

Achim

[Fraunhoffer]

That's s very interesting area to sketch. Thank you.