calculators & software

The US Naval Observatory site includes a flexible Virtual Reality Moon Phase Pictures, and a range of other tables and calculators including rising and setting times for a day or a year and a text-only phase calendar.

More graphical phase calendars have been developed by Paul Carlisle and by Tim Beauchamp at Googol.

Martindale's Calculators provide a JavaScript Astronomy Calculator which will calculate the dates of forthcoming principal phases, eclipses and, unusually, meteor showers. The U.S. Naval Observatory's Lunar Eclipse Computer is also a useful resource to calculate the circumstances of an eclipse from any location.

Obliquity offers an interesting Blue Moon Calculator.

If you use Windows 95, you can download a fun calculator for your system tray from Locutus, though you are warned that it is only accurate to within one day, and is unsuitable for scheduling your favourite rites!

T. Wesley Erickson offers a rather good (and free) Lunar Colongitude program. Moontool, from John Walker's Fourmilab is a real-time open-source lunar phase calculator.

Alister Ling has produced several Windows-based programs available from the Royal Astronomical Society of Canada. Lunar Calculator is a very impressive tool for calculating phase and libration and displaying maps to illustrate them. The Clementine Skimmer creates a zooming and panning map based on Clementine imagery and cross-referenced with a feature database.

Moon Manager by M.Power and S.Mason is a DOS-based interactive lunar map, and can be downloaded from UK Mirror.

The excellent DOS-based Moon Calculator by Dr Monzur Ahmed generates local sky charts and global crescent sighting maps. Download it from its home page.