Lunar crater size

[Nigele2]

With the moon in my lense even with just my 25mm EP I can see craters with great clarity    Some very big, some in comparison quite small.  But how small? (when I say crater I mean a circle with a centre so it is obviously a crater).

I know the moon has a diameter of just over 2000 miles.  The smallest craters I can see (in the centre) with clarity would probably fit 70 times (a rough guess) into that diameter.  So that might make them 30 miles across.  

With my f11.7 (700/60) refractor and 9mm eye piece (no barlow) does that sound about right?  

I was also wondering how big the first lunar manmade city would have to be for me to be able to see it? 

[Freddie]

The map on here will tell you the size of the craters you can see.

http://www.moon.com.co/atlas/index.shtml

[Bizibilder]

Download the "Virtual Moon Atlas" - its very good and free!!

[Nigele2]

The map on here will tell you the size of the craters you can see.

http://www.moon.com.co/atlas/index.shtml

Freddie that is brilliant.  Gracias 

[John]

I've seen craters down to around 1.3 miles in diameter on the Lunar surface on nights of good seeing. A 60mm refractor ought to be able to show craters as small as 2-2.5 miles in diameter, if they are favourably lit.

[Nigele2]

Bizibilder thanks for that.  Should be able to find a few craters with that.  And enjoyed your blog.

I've seen craters down to around 1.3 miles in diameter on the Lunar surface on nights of good seeing. A 60mm refractor ought to be able to show craters as small as 2-2.5 miles in diameter, if they are favourably lit.

ok John you have set the target.  I'll see what I can do.

Last night was for sure very good here in Hampshire and the crators I could see were crystal clear with beautiful shadowing showing them off to great effect.

[AndyWB]

Yes, the moon was lovely last night. I think the big craters on the terminator were Hipparchus (138km) and Stofler (126km). Did you make out Rima Ariadaeus and Rima Hyginus? I've never seen them so clearly!

[Nigele2]

Yes, the moon was lovely last night. I think the big craters on the terminator were Hipparchus (138km) and Stofler (126km). Did you make out Rima Ariadaeus and Rima Hyginus? I've never seen them so clearly!

Rima Ariadaeus and Rima Hyginus!!!!  Wow Wow Wow only my second look and all those long words   

Andy I've got as far as the big thing at night must be the moon and the big thing in the day is the sun but don't go there.  But while you knew what you were watching and I thought 'nice crater man' I guess the great thing is we both appreciated it.   

Good to know there are star gazers nearby.  I'm in Kingsclere.

[AndyWB]

Ah! When I fancy a "big night out" I usually head over toward Walbury Hill, not far from you; Reading is dreadful for Light Pollution. There are quite a lot of folks from around here on here, though!

About half way up the terminator there were what looked like 2 hairline cracks in the moon. The angle of the light seemed to bring them out much better than I'd seen before. A nice, similar photo can be found here: http://www.flickr.com/photos/60071135@N02/7165958877 (thanks Google) . Rima Hyginus is slightly easier to spot as it has a crater slap bang on it.

(And no, I don't know where the names for these things come from)

[John]

The finest detail I'm managed to detect on the Moon is the rille that runs up the Alpine Valley. This feature is less than 1km across even at it's widest. I have only seen certain sections of this rille where it is more prominent and it needs excellent viewing conditions and high magnifications to detect with my 12" scope.

The craterlets in the floor of the large crater Plato are a good challenge as well. They range from 2.6km (the largest) downwards. Under favorable lighting conditions I've seen 6 or 7 of these with my 12" scope. The 4 larger ones are visible at high power with my 4.7" refractor. Here is a link to help identify which to target:

http://the-moon.wikispaces.com/Plato+Craterlets

[nightfisher]

Nice link John