I've been playing with this for awhile - and it does take awhile to figure out - but it's really pretty cool -

http://celestia.sourceforge.net/

I have family all over the globe - just looking at Earth with this is pretty cool (once you sync the time) with it's simulated city lights at night - I dunno if it works for Macs - and honestly, it took me about 1/2 an hour to figure out how to make it do exactly what I wanted it to...

But I think it's got gee whiz factor galore...

PM me if you have any problems running it...it really is a program worth running...I know my 7 year old boy will love exploring it.