Small heliocentric model shows earth and moon orbiting around the sun. It has two modes of operation, real time and simulation. In the real time mode current location of earth and moon are calculated and updated periodically. Earth makes one full orbit in one year and moon makes one orbit around the earth in 27 and half days.
In the second mode, time is running faster and you can see moon orbiting around the earth and earth slowly orbiting around the sun. Calculations are still as accurate as with the real-time mode though. One year takes a bit over one hour to complete in this mode. User can select between modes with easy to operate menu.
Model costs 200L$ and is made of 7 prims. Permissions are mod/copy, except for the scripts which are copy-only.
Available at:
In-World: http://slurl.com/secondlife/Blorkus/252/176/111
XStreet SL: http://www.xstreetsl.com/modules.php?name=Marketplace&file=item&ItemID=1136091
OnRez: http://shop.onrez.com/item/904191