Some Useful and Free Astronomy Software
View the sky and celestial objects. 3-D card and Open GL required.

Determine which part of a planetary surface is visible.


NASA has released a viewer program, World Wind, that allows for graphical displays of the Earth, our Moon, and planets in the solar system at a remarkable level of detail. Data for the program comes from a variety of satellites, and other sources. The program works best with fast computers, having a newer graphical display card and a fast internet connection. http://worldwind.arc.nasa.gov/.

Download Sundial Patterns

Create your own Sundials for any latitude using this program


Determine the central meridian and angular size of Mars using this Freeware program


Download this Freeware program for modeling the Solar System