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GeoAstro Applets |
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Chaos Game |
Java |
Miscel- laneous |
Physics Quiz |
Who is Who ? |
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Planet Applet Applet Details Planetary Events Solutions |
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Planet Applet: Mercury, Venus, Mars, Jupiter, Saturn, and the Moon |
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value derived from longitude: |
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Enter
latitude
in
decimal degrees and press return
key, |
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1.
a
Diagram showing the
rise and set times over the year, 3 different representations |
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Use the Planets, Moon menu items to show or hide the planets and the Moon. |
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The
items
of
the Details menu, working in toggle mode, show and
hide additional details. |
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You
may
use
the keys y, m, w,
d, h, n to increase the yaer, month, week,date, hour, or
minute, Use
c or shift key and c to increase/decrease the
century. |
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Choose
from
the
Write/Draw
... menu to write
data to a new window |
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You may enter your home location by editing the applet parameters of this HTML page. Details here. |
In case the applet is not running, click here
Planetary events to discover and to explore
1. Select "Diagram" from the View menu:
Redrawing the diagram will take some time because of 365 complex computations have to be done.
To
draw rise and set of a single planet select "None" from the
Planets, Moon menu
and then turn on the planet to show.
Example: Berlin, 2004 March 20:

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Rise Set
There
are three different representations of the diagram:
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To hide or show the current sun in the Diagram View choose "Sun" from the "Details" menu.
To show
the visibility of a planet select "None" from the
"Planets,Moon" menu,
and than the planet.

2004: Venus
visible
as
Evening Star (upper green regions)
or Morning Star (lower regions)

2004: Visibility
of
Mercury
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The
duration
of
the Astronomical Night |
2. Select "Horizon Rectang." from the View menu:
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This
equirectangular projection is a cylindrical equidistant
projection,
in which the horizontal coordinate is the longitude and the vertical
coordinate is the latitude. (x=λ, y=φ, equator as standard
parallel).
Extreme distortions near the poles.
To draw the diurnal path of the Sun select "Show Orbits" from the "Planets, Moon" menu.
3. Select "Horizon Spher." from the View menu:
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You
may
use
the keys m, w,
d,
h,
n to increase the month, week, date, hour, or minute |
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Use the Planets, Moon menu items to show or hide the planets and the Moon. |
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Click a celestial body to read its azimuth and elevation. |
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The
items
of
the Details menu, working in toggle mode, show and
hide additional details (if applicable). |
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magnitudes of planets |
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Altitude (Elevation) Azimuth |
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Right Ascension Declination The first equatorial coordinate of a star (St) is the declination delta, measured in degrees north and south of the celestial equator (N: 0° < delta < 90°, S: 0° > delta > - 90°. The second coordinate is the Right Ascension RA, measured along the equator from from a zero point known as the vernal equinox (V). |
A
screen shot of Walter Fendts applet |
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-6° < elevation < 0° -12° < elevation < -6° -12° < elevation < -18° elevation < -18° |
civil twilight nautical twilight astronomical twilight |
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The Julian Day and the Local Mean Sidereal Time are indicated. |
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Select "Sun" from "Choose Details" to see the path of the Sun, and the intersection angle with the horizon (alpha). By this angle the time interval for rise and set is computed (in minutes): 4*sunDiameter/sin(alpha) |
4. Select "Horizon Polar" from the View menu:
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or "Horizon Pol. Zoom":
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you
may choose details:
To draw the diurnal path of the Sun select "Show Orbits" from the "Planets, Moon" menu.
5. Select "Ecliptic" from the View menu:
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(from above the solar north pole)

or Select "Ecliptic Zoom":
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(not showing Jupiter and Saturn)

Ascending
node,
the
point where the planet crosses the ecliptic from south to
north. Perihelion
(Perigee),
the
point of closest approach to the Sun. Aphelion
(Apogee),
the
point furthest from the Sun. The
Earth-Moon
distance
is magnified by 25. The
red
line
is the Greenwich meridian. Use
the
keys commands h,
d, w, m to increase the hour, date, or
month, to observe retrograde motion. Use
the
"Planets,
Moon" menu to show or hide the Earth-Planet lines and the
orbits. For
Mercury
and
Venus the current elongation angle from the Sun is
displayed. The
opposition
or
conjunction of a planet is indicated in case the proper
month and date is selected. The
planet
is
above the ecliptic plane The
planet
is
below the ecliptic plane
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An eastern elongation angle means Mercury will be visible in
the western sky after sunset, while for a western elongation Mercury is
visible in the eastern sky before dawn.
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(heliocentric latitude is positive).
(heliocentric latitude is negative)
6. Select "Ecl. Earth/Moon" from the View menu:
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To switch off the lines choose "Hide Lines" from the "Planets, Moon" menu.
Watch
the retrograde rotation of the (green) line of nodes
(the
mean longitude decreases by about 19° per
year),
and the prograde rotation of the (blue) line of perigee (the
mean
longitude increases by about 41° per
year).
Lunar Perigee and Apogee Calculator
Applet: Computing the motion of the Moon
7. Select "Sky Map" from the View menu:
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The
ascending
node
of the Moon is indicated (grey oval). The
example
is
showing a loop of Mars (retrograde motion). Click
the sky map to show the coordinates. Command
key and click will draw a green cross mark. These
coordinates (RA and decl.) are indicated in the "Horizon Rectang.", in
the "Horizon Polar", and in the "Horizon Spher." view:

Choosing "Show Path" from the "Choose Details" menu will draw the
positions of the Moon for the current month and of the planets around
the current date:
+/-45 days for Mercury, Venus,
+/- 90 days for Mars, Jupiter,
+/- 120 days for Saturn.
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or
choose:

Use "Stars and Names" from the Details menu to show or hide star names.
Click
a star to show its name and magnitude:
8. Select "Earth Map" from the View menu:
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Use the Details menu to add more details (stars, bright planets, etc.):


A
celestial bodies (star, planet) is seen at the zenith by an
observer
located at the position of the body on the world map
(declination=latitude, hour angle=longitude).

Click
the map to get the location, or the latitude and longitude

Select
"Altitudes Sun" from the details menu to draw lines of equal Sun
altitudes
Data and Graphics windows:
Choose
from the Write/Draw ...
menu
Dates
of
New
Moon and Full Moon for the year selected, and lunations. Local
Full
Moon
Transit Elevation Dates
and
times
of the node passages of the Moon. Dates
and
times
of the perigees or apogee of the Moon. Anomalistic
Month Extreme
ecliptic
latitudes
of the Moon (diagram) Extreme
declinations
of
the Moon (diagram) The
window
"Data
Sun and Moon" : -
the date and time of solstices, equinoxes, perihelion and aphelion for
the current year. -
the date and time of New and Full Moon for the current month (UT is
accurate within +/-1 hour). -
the date and time of the Moon's perigee and apogee for the current
month. The
hours
(UT)
are accurate within +/-1 hour). Table
showing
the
begin (end) of nautical and civil twilight (depression
6°), the sunrise (sunset), and the duration of civil and nautical
twilight. List
of
the
Equation of Time (at 12 UT) and the daily change. Perigee,
Apogee Planetary
separations
(in
geocentric longitude) of less than 5° (or 10°,
or 3° when opened again) taking place more than 10° from the
Sun. Opposition,
conjunction, Lunar
Eclipses: The
brightest
stars
(mag<2), and their rise, transit, and set time. The
locations
available
from the Location menu. Sunrise
and
sunset,
civil, nautical, and astronomical twilight, daylight hours. Sunrise
and
sunset,
civil, nautical, and astronomical twilight, daylight hours Sun &
Plan Month Sunrise
and
sunset,
civil, nautical, and astronomical twilight, daylight hours, Positions
at
0:00
UT: Sun Alt
& Azim Day Altitude
and
azimuth
of the sun for the date selected. Altitude
and
azimuth
of the Moon for the date selected. Altitude
of
the
Moon at transit for the location and year selected.

Draw
Geocentric Motion
Draw
Opposition Loop
Draw
Equation of Time
Draw Planet
Phases
Draw diagrams:

Create a table of the
dates of conjunctions and phases.
Synodic Month
(diagram)
Draconic Month
Moon
Alt/Az/Phase
Altitude, azimuth and
illuminated fraction of the Moon for any day of the month selected (1
hour interval).
The mean error is less than 1 second.
node passages (ascending, descending).
max. Elongations of Mercury and Venus.
looking for Full Moon (difference of geocentric longitudes 180°,
opposition) and ecliptic latitude <+/-1.5°
Solar Eclipses:
looking for New Moon (difference of geocentric longitudes 0°,
conjunction) and ecliptic latitude <+/-1.5°
details about daylight hours, latest sunrise, and earliest sunset.
Sun & Plan Yr
rise and set of the planets and the Moon.
Apparent Heliocentric Position: longitude, latitude, distance.
Apparent Geocentric Positions (True Equinox and Ecliptic
of Date)
Ecliptic System: longitude, latitude,
and Equator System: right ascension, declination, distance,
errors: longitude +/- 0.01°, latitude +/- 0.001°.
Compare with
MICA (Multiyear Interactive Computer Almanac, U.S. Naval
Observatory)
Zodiac
the Position of
the Sun, Moon and planets
Sun Alt & Azim Hr
(diagram)
Geocentric
Motion:

Details for the
opposition loops of Mars
Retrograde
motion
is
occurring for the outer planets at their opposition,
and for the inner planets at inferior conjunction.

Planetary
Phenomena
Eclipse
Home Page (Fred Espenak)
APPLET Parameters:
You
may enter your home location and change some settings by editing the
applet parameters of the HTML page.
Open "index.html" in Netscape's Composer, in any HTML editor or in
Windows' editor.
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<APPLET
CODE="planets113.class" WIDTH=780 HEIGHT=580 ALIGN=bottom
archive="applet/JavaClasses.jar"> |
Do not change. |
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<PARAM NAME=location VALUE="Berlin"> <PARAM NAME=latitude VALUE="52.51"> <PARAM NAME=longitude VALUE="13.41"> |
Edit the text of the location parameter, and
the
values
of the latitude and longitude parameters
(decimal degrees). |
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<PARAM NAME=background VALUE=0> |
Set
the
background parameter value to 1 |
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<PARAM NAME=image VALUE=sunview> |
Change
the
image parameter value to sunview1 |
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<PARAM NAME=startview VALUE=2> |
Set
the
startview parameter value to |
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</APPLET> |
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© 2003-2010 J. Giesen