Lunar Calculator

Plan your lunar observing: zoom in, identify craters, search librations, alt/az, for photo opportunities

Lunar Calculator

LC23 install package (13MB) change .pro to .exe before running. 

Freeware/shareware. Registered users receive a security key to access full functionality. Click on the title above to begin download. change .pro to .exe, then click on the EXE to self-extract, and it will auto-install. Then run lunv2.exe. No need to restart the machine. For Vista/Windows7, you will have to run this in Win95 mode. For the time being, this version remains frozen. I hope to return to programming before the end of the decade.

This v2 release has SEAMLESS Clementine display. Check out the screenshots for more details.



Includes blended USGS-Clementine rendering!

Yes, those are crater rims and peaks on the dark side of the terminator!


  • over 7,400 craters, mons, etc including landing sites
  • full 3-D accurate topocentric libration
  • upside-down and mirror reversed capability
  • USGS texture, Clementine imagery, USGS-Clementine blend, wire frame
  • Clementine and USGS high resolution imagery to 0.5km (0.3 mile) per pixel
  • Dynamic shading of the USGS map: reversed highlights/shadows for post full Moon time, reduced texture for high Sun angles away from the terminator, and crater rims and peaks on the dark side of the terminator
  • re-sizeable up to 1200x1200
  • contrast/brightness/earthshine control
  • "go to" and "identify" features
  • crater outline and grid overlays
  • choice to create orthographic/geocentric rendering
  • animating libration graphs; notes full Moon and whether limb light/dark
  • search for similar or stronger librations
  • search for young and old crescents that satisfy your criteria
  • floating "bullseye" scale.
  • navigation Box: In a mini-window, the current view is outlined on the full disk.
  • toggle on/off maria/mountain chain markers.
  • toggle on/off the RASC IKW features (Isabelle K Williamson)
  • calculates distance between 2 clicked points
  • schedule/table of libration/colongitude values
  •  added illumination and elongation to most output
  • IKW (Isabel Williamson) Lunar Observing Program features (from RASC, Royal Astronomical Society of Canada)
  • searches for altitude/aziumth conditions to satisfy your visual and photographic needs
  • user specified (artificial) librations
  • user specified prefered magnifications
  • automatic grid spacing
  • multiple observatory sites
  • multi-language support! English, Deutsch, Italiano, Français are available.
  • detailed HELP file

No further updates are being planned for the forseeable future.
The registered version of Lunar Calculator v2.3 can be obtained for US $20 from:

Alister Ling
473 Burton Road
Edmonton, AB
Payment can be in US cheque or money order. Sorry, no credit cards or paypal.
Even if you already have the Clementine CD, there is no price reduction because the delivery CD contains over 90 Meg of special image files.

What Clementine/USGS imagery is included?

  • Registered users receive the NASA Vol 15 Clementine LDIM CD at no extra cost.
  • Registered users also get the USGS texture map at 0.5 km (0.3 mile) per pixel
  • In the free Lite mode, Lunar Calculator comes with Clementine imagery and USGS texure map and blends at 5 km (3 mi) per pixel, and has no expiry date . However, it is limited to a 35 day interval on each side of the day you run the program. In other words, if today is June 10, 2013, then the Lite version will work for days between May 5, 2013 to July 15, 2013. Also it will not plot the smallest features (less than 3km/1.8mi).

Low res animation of a lunar month from Lunar Calculator