Question about the moon

[JarrydS]

Hey guys, just thought id ask a question about the moon, as i am sitting outside with my scope and viewing the pretty much full moon, i was having a good look and on the right side of it i can see what i believe to be some sort of large impact spot? It's like there is a crater in the center with multiple lines going on all directions around it, when i say lines i mean it looks like a large amount of dust or something has been pushed into every direction, like you see with shrapnel in an explosion. Is this a impact crater or is it just some sort of other fascinating thing im viewing?

[renormalised]

It's an impact crater, with crater rays splayed out in all directions. It's most likely the crater Tycho.

[JarrydS]

Thanks for that, it looks really great.

[erick]

Great view isn't it! Keep looking. You should see two others that show much the same, but the rays are not quite as extensive - craters Copernicus and Kepler.

[Clarry]

The spray indicates it's a newer impact. I'm not talking days here, more like hundreds of thousands of years or maybe millions, not too sure.

[erick]

"Tycho (85 kilometres dia) is a comparatively fresh impact crater with a vast ray system of ejecta material spanning almost 1,500 kilometres across the lunar surface."

Copernicus (107 kilometres dia) - "Its striking terraced walls, grouping of small central peaks and radial ejecta rays out to 800 kilometres make it a stunning sight in any astronomical telescope."

Kepler (31 kilometres dia) - "Kepler is a small, young, lunar crater. Despite being just 31 km in diameter the crater and its associated system of rays is visible from the Earth." "The crater itself is 2.6 km deep and contains evidence for terracing and a central peak and is of similar age to the Lichtenberg crater, and the more widely known Copernicus and Tycho craters. In common with these last two, Kepler also contains a series of bright rays stretching around 300 km from the crater."

[jjjnettie]

You should download a copy of Virtual Moon Atlas.
http://sourceforge.net/projects/virtualmoon/files/

[Darth Wader]

Just downloaded the "lite" version of this - fantastic! Cheers Jeanette:thumbsup:

[dannat]

you can get a rough age guide of a crater/impact by counting how many smaller impacts are there. lots of little craters = old, only a few craters = fairly recent

[jjjnettie]

Yer welcome! :D

[mithrandir]

It all depends on your download limits and disk space. 422MB is less than my star catalogs for Stellarium. :)

[jjjnettie]

There's a tiny, very basic version of the programme out there on the net, somewhere. Only a couple of MB in size.