MoonDock is a lightweight application designed for displaying up-to-date images of the Moon phase in your system Dock or as a floating Moon image on your desktop. MoonDock also allows examination of Moon phase information for specific dates and times between 2001 and 2015. If you're an amateur astronomer, learning about the night sky or just like to have the Moon on your desktop this is for you.
When first run MoonDock displays auto-updated images of the current Moon phase in the Dock. If you'd like you can set MoonDock to start-up when you first login to your computer by dragging it's icon into System Preferences, Login, Login Items tab. Otherwise just run it when ever you need too. MoonDock has been designed to be resource sensitive and can happily be left running in you Dock if desired.
MoonDock can also be configured to display a floating Desktop Moon image of the current phase. The image can be dragged any where on screen, have it's size, transparency and drop-shadow defined. It can be set to float above all other windows or stay in the background. A reset button is provided to quickly get back to the default image settings.
By default, the main information window will open - this shows a range of information relating to the Moon phase. From here you can switch MoonDock to display Custom Dates and Times, allowing you to scroll through Moon phase information and imagery between 2001 and 2015. Switching back to Todays Date and Time returns MoonDock to it's default behavior of displaying current Moon phase information in real-time.
When set to Todays Date and Time, information and imagery is updated on the cusp of each new minute, system cpu utilization has been kept to a minimum and all Moon images have been pre rendered.
The behavior of the main Information window can be configured in a number of ways depending how you'd like to use MoonDock. A common requirement is to hide the main information window at launch time so that you can have MoonDock set to launch at system start-up time without opening unnecessary windows. See MoonDock->Preferences under the Information Window tab.
For additional help hints while using MoonDock, place your mouse cursor over a specific information field and pause for a moment - a short help hint description about the information field will appear. MoonDock also includes a small catalogue of named luna surface features, placing the mouse cursor over visual areas of interest on the Moon image displays the feature name.
The Quick Answer: Ooooh, hmmmm, well, errrrr... From my research MoonDock is accurate to about a minute for new Moon and full Moon calculations (dates between 2001-2015). Dates out with these years can not be displayed.
The Long Answer: There are so many ways to calculate Moon phases. Some are quite accurate, most are just approximations but all suffer from errors of varying extents. 'Why?' you ask 'in this age of super computing for all.' Well all calculations are based from measured observations and known laws of motion and physics. These are then used to predict the movement over time - the more accurate the measurements and theory, the better the prediction. The calculations need to take into account an _awful_ lot of physics to be any good, everything from the varying density of the Earth crust, drag caused by the oceans tides (which are caused by the Moon and Suns gravity) and positions of the other planets in our solar-system. If you'd care to see some of the maths, NASA has sample Fortran code available in its archives - but be warned it's hard core number crunching! So, how does MoonDock do it? Well after trying some of the simpler mathematical solutions and being less than satisfied with their accuracy I've opted for an interpolated look-up table using data from a reliable source (Astronomical Applications Department of the U.S. Naval Observatory http://aa.usno.navy.mil/). MoonDock references their accurate data tables to interpolate the rest of it's phase prediction information between 2001-2015.
MoonDock can display New Moon and Full Moon information in both Universal Time (UTC) and Local Time. Local time is dependent on your computers current locale time-zone settings, while UTC is based on Greenwich Mean Time (+0000hrs). See your System Preferences for information on setting your time-zone correctly. The Next New Moon and Next Full Moon times can be displayed in either Universal Time or Local Time, preferences can be found under the menu MoonDock->Preferences... in the Date and Location tab
Throughout each day, Moon phases look very similar at any given point on the Earth's surface. However depending on which hemisphere you are viewing from you will be accustomed to seeing the Moon at a particular orientation. MoonDock defaults to assuming you are viewing from the Northern Hemisphere but you can change to a Southern Hemisphere preference under the menu MoonDock->Preferences... in the Date and Location tab
New Moon: The new Moon is very hard to observe as it rises and sets so close to the Sun's position in the sky. This is the time when it's possible for a solar eclipse to occur but due to the small visible size of both the Sun and the Moon disks it happens very rarely. You may get a glimpse of the Moon's unlit disk just before sunrise or just after sun set before the sky gets too bright.
First Quarter: The Moon rises after the Sun is up, while your in full daylight, so you'll not get a good view until the Sun begins to set and the sky darkens. As the sky darkens the Moon will be high and/or towards the west.
Full Moon: The full Moon rises in the east at about the same time the Sun sets, then sets in the west at about the same time the Sun rises - so it's quite easy to observe on a clear night. The Moon rise and set times, opposing the Sun's, are because full Moons occur when you (and the rest of the Earth) are directly between the Moon and the Sun. This is also the time when it's possible for a luna eclipse to occur (the Moon hidden by the Earth's shadow). Due to the Moon's slightly offset orbit, luna eclipses are quite rare as it usually misses the Earth's shadow.
Last Quarter: The Moon rises late at night when the sky is dark and can be seen over in the east of the sky. By the time it reaches it's highest point in the sky the Sun will be beginning to rise making viewing less easy.
What features would you like to see added to MoonDock? If you have any feature suggestions you think will improve MoonDock please do email me and I will try to include your suggestions in subsequent releases. My thanks go to all those who have already provided feedback and suggestions.
firstname.lastname@example.org personal e-mail
http://homepage.mac.com/garycmartin/ web (MacOS X development)
http://www.geocities.com/garycmartin/ web (CG imagery)
MoonDock is provided "as is," without warranty. Its developer disclaims all warranties and conditions, either express or implied, including, without limitation, warranties of merchantability and fitness for a particular purpose. Use this software at your own risk. The developer suggests that MoonDock is not used for planning your next luna space mission.
http://aa.usno.navy.mil/ Astronomical Applications Department of the U.S. Naval Observatory
http://www.fourmilab.ch/earthview/vplanet.html Earth and Moon Viewer
http://nssdc.gsfc.nasa.gov NASA National Space Science Data Center
http://www.fourmilab.ch/earthview/pacalc.html Lunar Perigee and Apogee Calculator
http://www.shallowsky.com/moon/hitchhiker.html The Hitchhiker's Guide to the Moon
http://www.btinternet.com/~kburnett/kepler/index.html Keith Burnetts Astronomical calculations