Moon Distance Applet

The applet is also computing the geocentric and topocentric distance of the Moon from the Earth (accuracy better than
+/- 10 km between 1900 and 2050), the apparent angular size (arc minutes), the illuminated fraction of the Moon's disc (per cent), and the Moon's phase:

0.00 = new Moon
0.25 = first quarter
0.50 = full Moon
0.75 = last quarter
1.00 = new Moon

The altitude is taking into account the horizontal parallax of the Moon.

	Distance / km
Perigee	356,375
Mean	384,401
Apogee	406,720

The computations are performed following Jean Meeus.

Select "Write Data" from the Details menu:

F(EM)/F(SM) is the ratio of the gravitation forces between Earth and Moon F(EM) to Sun and Moon F(SM).
The mean value of about 0.45 for the Earth's Moon is unique in the solar system:
Details

The axial tidal acceleration a by the Moon is approximately:

tidal force formula

Earth's radius r=6371 km, Moon's mass =7.349 10²² kg, distance Earth-Moon R (356.000 km < R < 407.000 km).

tidal acceleration diagram

More about tides

Select "Diagram" from the Details menu:

earth moon distance

The change of distance may be up to about 6,300 km per day.

The mean perigee distance of 284 anomalistic months is 362562.4 km.

The maximum lunar declination 23.44° + 5.15° = 28.6° (Major Lunar Standstill in 2006):

At 28.6° N or 28.6° S the daily topocentric difference of the Moon's distance from Earth will reach the diameter of the Earth.

At the North pole the topocentric lunar distance will have no diurnal change: