I've been trying to tune up some of my telescopes for the upcoming Mars event. In late August, Mars will be closer to the earth than it has been in all of recorded history. While surfing around, I noticed that there was a Python package called PyEphem
which provided Python bindings for the popular
Xephem program. It's remarkably easy to deal with, in a few minutes I had a script which computed the apparent size and magnitude of Mars and printed them out. A much longer time was spent trying to understand how to use the gdchart module, but the results turned out the nice charts you see here.
The apparent brightness is in apparent magnitude, where negative numbers are brighter. When Mars is at its closest approach, it will outshine everything in the night sky except the moon. (I wasn't able
to figure out how to get Python's gdchart module to display the graph
with the yaxis reversed. I'll keep at it.