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                      education, software, applet, java, shareware

                    education, software, applet, java, shareware
Chaos Game
                      education, software, applet, java, shareware
                    education, software, applet, java, shareware


Moon Phase Applet

The moon icon indicates the current phase.

Current Moon phase applet

The applets is also computing the duration of lunations, i.e the time interval between successive New Moons. In addition the right column is showing the difference between the duration of that lunation and the mean value of 29 days, 12 hours, 44 minutes (29.5306 days).

You may use the key "y" to increase the year, or shift key and "y" to decrease the year.


long duration
short duration
New Moon 2000 Dec. 25
New Moon 2001 Jan. 24
duration: 29 d, 19 h, 45 min
(mean + 7 h 1 min)
= 29.8229 days
New Moon 2001 Jul. 20
New Moon 2001 Aug. 19
duration: 29 d, 7 h, 11 min
(mean - 5 h 33 min)
= 29.2993 days

Press the "write" button
to open the data window

 moon phase distance

Table: Biggest and smallest Full Moon

A Blue Moon is the second full moon in a calendar month. Usually months have only one full moon, but occasionally a second one sneaks in. Full moons are separated by 29 days, while most months are 30 or 31 days long; so it is possible to fit two full moons in a single month. This happens every two and a half years, on average.


How to get the applet version for offline use  

Please visit my "MoonYear Applet"

Visit my page: The Moon: orbit and phases

Please visit my:

GeoAstro Applet Collection

Web Links

Inconstant Moon (Fourmilab, John Walker)

Lunar Perigee and Apogee Calculator (Fourmilab, John Walker)

A Whale of a Full Moon (NASA Space Science News)

Astronomy Picture of the Day, December 22, 1999 (NASA)

Warum ist der Mond am Horizont so groß?

The Moon Illusion,An Unsolved Mystery.

Explaining the moon illusion

The Face of the Moon from Galileo to Apollo

Last modified: 2023, Oct 04