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the Moon for a day
         the Moon for a year

Position of the Moon by Spreadsheet
for a month

download

Select the table 'input': moon
                position month

Input (red frames):

1) hour UT, min

2) month, year

3) geogr. latitude und longitude
    (eastern longitude positive)

Don't modify any other cell.

moon position
The table 'calc' performs the calculations, using a lot of auxiliary variables. Don't edit any cell. moon position
Select 'elev az_illum' to see data and diagrams of elevation, azimut and illumination.
Select 'distance declin' to see data and diagrams of geocentric distance and declination. moon distance
                declination
Select 'orbit' to see the orbit of the Moon around the Earth. orbit of the moon
Select 'L  B' to see data and diagrams of ecliptic longitude and latitude. moon latitude longitude
Select 'sol ecl' to explore solar eclipses. solar eclipse
Select 'lun ecl' to explore lunar eclipses. lunar eclipse


Example: 2000, Jan,  0:00 UT at 50°N, 10°E:

elevation azimuth

position
        moon elevation altitude spreadsheet download


moon position month
        spreasheet download

Comparing the results of airless elevation of my spreadsheet with the 4 decimal places of MICA
the mean absolute error is only (0,036 ± 0,018)°.


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The illuminated fraction k of the moon is geocentric, computed (Meeus, Astronomical Algorithms, Ch. 46) by:
k = [1+cos(i)]/2
cos(i)= cos(Bmoon) cos(Lmoon-Lsun)

moon year
        position Excel spreadsheet download


Comparing my results for the illuminated fraction of the spreadsheet (geocentric) with the 1 decimal values of MICA
the error is  (0,02 ± 0,03) %.

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moon position
            spreadsheet excel download

Azimuth is measured North(0°) -> East(90°) -> South(180°) -> West(270°) -> North (360°).


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Position of the Moon, on 2000 Jan, 0 UT at 50°N, 10°E:

moon position elevation
        altitude azimuth

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moon distance

Geocentric distance and declination

2000, Jan,  0:00 UT
 
 
The geocentric distance of the Moon is computed by Meeus (Astronomical Algorithms, Table 45.A, 46 trigonometric terms):

moon distance

The mean absolute error in Jan 2000 at 0 UT is (3.0 ± 1.7) km,
reference:
MICA

error
              distance 



The mean absolute error |∆R| on Jan 1 at 00:00 UT in 1850 to 2050 is (3.3 ± 3.0) km,
reference:
MICA

*****
topocentric distance

At 50°N 0°E the mean abs. error in Oct. 2022 at 00:00 UT (reference MICA) is
(3.4 ± 2.6) km

*****

topocentric
                  distance of the moon
2022 Jan at 50°N 0°E

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The topocentric diameter of the Moon, 2000 Jan at 00:00 UT:
moon apparent
                  diameter

The diameter is computed by the equatorial horizontal parallax (Meeus, Astronomical Algorithms, ch. 39, 53).

Comparing the results "diam" of my spreadsheet with the values of HORIZONS Web-Interface
(NASA JPL) the mean absolute errors "∆diam" are in arcmin:

moon
                    apparent diameter

A large full moon occured on 2019, Feb 19 at 00:00: diameter 33.97 arcmin (
HORIZONS Web-Interface)
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The extremes in the Moon's negative/positive declination ranges
from about -18.2° to -28.7° and +18.2° to +28.7° in a period of 18.6 years:

declination moon
              standstills


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moon orbit

The orbit of the Moon around the Earth (Jan 2000):

 
eclipse






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moon latitude longitude

Ecliptic longitude Lm and latitude Bm

2000, Jan,  0:00 UT
moon
        latitude

moon latitude longitude



angular velocity moon

Perigee (max. velocity): Jan 19, 22:47 UT (fourmilab)
Apogee (min, velocity): Feb 1, 1:31 UT (fourmilab)





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solar eclipse

Explore the conditions for solar eclises:

|Lsun-Lmoon| 'small'  and |Bmoon| 'small'

2000, Jan,  0:00 UT
solar eclipse 

solar eclipse


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lunar eclipse

Explore the conditions for solar eclises:

|Lsun-Lmoon| -180° 'small' and |Bmoon| 'small'

2000, Jan,  0:00 UT
 
lunar
                                    eclipse


moon eclipse






Download speadsheet (Windows und Mac):

moon_month.xlsx   (MS Excel)

moon_month.ods (LibreOffice, recommended)

Updated!



Web Links

Die Zeitgleichung: Eine einfache Formel zu Sonnenaufgang und Untergang

General Solar Position Calculations (PDF)

Solar Calculation Details

MICA (Multiliyear Interactive Computer Almanac 1800-2051), US Naval Observatory 2011, no longer published

Monthly Lunar Standstills: 2001 to 2100

2022, Oct. 23