Home

Site Map

Search

astronomy,
                      software, applet, java, shareware,sun, moon
GeoAstro
Applets

Astronomy
astronomy,
                    software, applet, java, shareware,sun, moon
Chaos Game
astronomy,
                      software, applet, java, shareware,sun, moon
Java
astronomy,
                    software, applet, java, shareware,sun, moon
Miscel-

laneous

Planet Observer Applet

Sun, Moon, and Planets

Get this applet for offline use



Select northern latitudes positive, southern negative,
eastern longitudes positive, western negative.
(52 31' N, 13 25' E is Berlin, Germany, UT + 1h)

To use the key commands,
at first click into the red frame of the applet !

Key
Function
d
1 day forth
shift + d
1 day back
m
1 month forth
shift + m
1 month back
space
current date

planets

Hold down the key "t" while selecting the planets to add the twilight times to the table.

Daylight
Select "Sun, Rise, Set" from the "Details" menu

daylight duration

Duration of civil twilight (rise/set to -6 altitude):
duration of
                          twilight

Rise and Set


The visibility of a celestial body depends on the latitude of the observer and on the declination of the body:
  • it is continually visible above the horizon during the entire  diurnal travel (no rise or set) if
    latitude + declination > 90 (northern hemisphere)
    latitude - declination < -90 (southern hemisphere)
    visible all day

  • it will never rise above the local horizon (no rise, set, or transit) if
    declination - latitude < -90 (northern hemisphere)
    declination - latitude > 90 (southern hemisphere)
    invisible all
                                    day

The last column of the applet is showing:
  • daylight hours (from rise to set of the Sun),
  • the illuminated fraction of the Moon, and the phase
    (+) waxing, or (-) waning,
  • the visual magnitude of the planets.

The Moon

The Moon rises about 51 minutes later each day. Therefore there are days without rise, transit, or set, which occur about every 29 days (12 or 13 times per year):

Moon rise set transit
                    table

To print the table copy and paste it into any text editor.

The times referr to the same calendar day, for example:
on Mar 02, the Moon rising at 11:08, transit at 19:30, will set at 03:46 next day. At 03:03 the moon is setting, which rised at 10:16 the previous day.

Extreme magnitude of the planets:

magnitude
                          planets


Rise time of Mercury, Venus, and Mars in 2012


rise transit set mercury

Venus sun set
        evening star

From January to May Venus sets later than the Sun (blue),
and will be visible as evening star.


Mars rise
        set transit diagram graph

Select "Horizon" from the "Details" menu to open the local horizon view:

topocentric view
        horizon sun moon planets

Mercury and Venus: magnitude and angular separation from the Sun

magnitude amgular
        separation


Select "Ecliptic" from the "Details" menu  to open the ecliptic view:

ecliptic

Web Links

Why does the moon rise 50 minutes later each day?


jgiesen(at)t-online.de

Updated: 2023, Oct 06