Observing Luna with my ED 120 refractor.

[Guest]

Just enjoyed an hour observing the Moon. Very clear and sharp with relatively settled viewing/seeing.

Lots of craters bagged. But how many with central peaks. Well four that I could identify using my Hamlyn Atlas of The Moon by Antonin Rukl. I observed Copernicus. Reinhold, Lansberg and Eratosthenes. These were on plates 31 & 32. The area was Mare Insularum and Sinus Aestuum.

Thinking of the large craters with central peaks. I understand how the central  peaks form after an impact. But why are there some craters, equally as large. But with no central peaks and smoot floors?

I am enjoying observing The Moon and then later identifying what I observed by studying this atlas. I must say that it is a quality Luna atlas. Very user friendly with clear maps and name labels.

Makes me sound like a seasoned Luna observer.

Who knows, I may get myself an astronomy drawing kit. Wonder if such a set is available to buy?

Must get a pair of Luna observing sunglasses ( did I just say Luna sunglasses?).???

Very bright is the Moon.

 

[Knighty2112]

No expert, but I think it depends on the angle the object hits the moon to form central mountains in a crater. The shallower the angle the less likely any mountains will form. The steeper the angle I think the ground rebounds upwards again after impact causing the mountain(s) to form. 

[Pig]

Nice session, the Moon is looking great tonight despite the freezing conditions. There is a link below about lunar craters and it explains why they differ.

https://en.m.wikipedia.org/wiki/Lunar_craters#Lunar_crater_categorization

[Guest]

Thanks for that Knighty and Pig.

[mikeDnight]

Sometimes it seems that magma fills the crater creating a smooth floor, such as Aristarchus and Plato. They make fascinating subjects for study, as they often reveal subtle changes in detail on the floors as the sun rises or sets over them, that are not recorded in lunar atlas's. Some ringed planes can be filled by lava from external impacts that then flood the smaller crater creating the ringed plane.

Attached is a sketch of Balmer who's floor has been flooded.

[Alan White]

Grumpy, sounds like you would enjoy the Moons course from Future Learn, it's free.

www.futurelearn.com/courses/moons