The Grumpy Old Astronomer's
Internet Applications

Free Astronomy applications created for the Internet:

Dark Sky Calculator

When will the sky be dark this month?
It can also produce a host of other astronomical information in
a printable monthly calendar format for anywhere in the world.

Messier Marathon Planner

Plan and print your Messier Marathon observing session strategy
for anywhere in the world.

Night Sky Planner

Generate and print a customized table of what's visible on any night
for anywhere in the world.
Astronomical Time

Displays Local and GMT time, astronomical (sidereal time),
and Julian date and time on your device.
(with "night vision" mode).