Position of the Moon by speadsheet

start

the Moon for a month the Moon for a day

Position of the Moon by Spreadsheet
for a year

Select the table 'input':
Input (red frames): 1) hour UT, min 2) year 3) geogr. latitude und longitude (eastern longitude positive) Don't modify any other cell.
The table 'calc' performs the calculations, using a lot of auxiliary variables. Don't edit any cell. Just ignore it.
Select 'elev az' to see data and diagrams of elevation and azimuth.
Select 'illum' to see data and diagrams of the illuminated fraction.	$illuminated fraction$
Select 'distance declin' to see data and diagrams of geocentric distance and declination.
Select 'L B' to see data and diagrams of ecliptic longitude and latitude.
Select 'sol ecl' to explore solar eclipses.
Select 'lun ecl' to explore lunar eclipses.

Example: 2001, 0:00 UT at 50°N, 10°E:

moon elevation
azimuth

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moon year
position Excel spreadsheet download

The atmospheric refraction is calculated ("elevRefr") by
1.02/(60*tan(K*(elev+10.3/(elev+5.11))))

Comparing the airless elevation results of my spreadsheet with the 4 decimal values of MICA
the mean absolute error is (0,016 ± 0,016)° in 1990 to 2050.

Azimuth:
moon azimuth

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

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At 50°N 15°E the abs. error at 00:00 UT for 1st of month (reference MICA) is
(2.8 ± 2.0) km

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$illuminated fraction$
The illuminated fraction of the moon is geocentric.

moon year position Excel
spreadsheet download

Comparing the results "Lmoon" (ecliptic longitude) of my spreadsheet with the 7 decimal values of HORIZONS Web-Interface
(NASA JPL) the mean absolute error in 1850 to 2200 is (0,52 ± 0,28)°.

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

In 2001 the smallest perigee distance is that of Feb 9 at 0 UT: 358,006 km.

According to Meeus (Astronomical Algorithms, chapter 48),
extreme perigee and apogee between the years 1500 and 2500 occur:
on 2257 Jan 1: 356,371 km
on 2266 Jan 7: 406,720 km

Results of my spreadsheet moon_day:
356,374 km at 13:00 UT
407,716 km at 7:30 UT

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The declination of the Moon in 2001:

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.

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Explore the conditions for solar eclises:

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

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Explore the conditions for lunar eclises:

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

Lunar eclipse data (NASA):
2001 Jan 09, 20:21:40, Total (day 9)
2001 Jul 05, 14:56:23, Partial (day 186)
2001 Dec 30, 10:30:22, Penumbral (day 364)

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Download Excel speadsheet (Windows und Mac):

moon_year.xlsx (MS Excel)

moon_year.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

2022, Oct. 23