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CELESTIAL CELEBRATIONS: NIGHT OF THE PLANETS Free Public Star Party to Observe
Venus, Jupiter and SaturnTwo March Evenings
Powell Hall Exhibition Center
Hosted by the AAC and the
Florida Museum of Natural History
Update: Tuesday evening (only) has been CALLED OFF due to weather forecast.
Wednesday evening is still on - and the forecast looks promising!
Planets are not always visible in evening skies. But during late winter and early spring 2004,
three planets hover in the sky ideally suited for telescopic observation
THE PLANETS Venus, Jupiter, Saturn and Mars now shine shine in evening skies. (Mercury also makes an occasional appearance.) Mars, now far from Earth, no longer shines bright and its disk is disappointingly small. But Venus, Jupiter and Saturn glow brilliantly in the heavens and are beautiful objects seen through telescopes.
The Alachua Astronomy Club, Inc. and the Florida Museum of Natural History celebrate these three planets by hosting free, public star parties during two successive, March nights.
What See the planets Venus, Jupiter and Saturn through telescopes provided by
The Alachua Astronomy Club, Inc.
What Might I See?
Where In Front of Powell Hall
Education & Exhibition Center
Florida Museum of Natural History
SW 34 Street & Hull Road, UF Campus, Gainesville FL
See Powell Hall for Exact LocationDates Two Consecutive Nights: Tuesday, March 16 and Wednesday, March 17
Update: Tuesday called off due to weather forecast.
Wednesday is on and the weather looks promising!Time 7:00 till 10:00 p.m. EST
The Museum will be open for restroom access on each of the two event dates
Museum exhibits will be open to visitors for extended hours from 7:00 to 10:00 p.m.
The Museum will hold the events weather permitting
For more information, contact Dr. Patti Anderson, Museum Education Coordinator
352-846-2000, Ext. 206
Each Image Below Approximates View of Planet Through a Telescope
(Moderate magnification — depends on your monitor size and resolution)
« Move cursor over each image to view an annotated figure (and click image to enlarge 3x) »
Depending on atmospheric conditions, telescope size and quality, eyesight, experience of observer, etc., you may see more or less. Positions of satellites change hourly and daily so satellites may not appear in positions shown.
Image orientation may differ in your telescope and may also be
inverted or reversed in telescope depending on the telescope's optical design.
VENUS — Second Planet from Sun & Sixth Largest Planet
VIEW THROUGH TELESCOPE
(Moderate Magnification)
Move cursor over image to view annotation or click to enlarge 3xFAST FACTS
(For the Technically Minded)
Distance from Sun 0.72 of Earth Orbit Period Around Sun 225 days Diameter 0.95 of Earth Rotation Period 243 days (retrograde) Mass 0.82 of Earth Density 5.2 x water Bulk Composition Rock; narrow atmosphere Atmosphere Carbon Dioxide (96%);
Nitrogen (3.5%)
Mid-March 2004Distance from Earth 120 million km or
75 million miMagnitude -4.3 Angular Diameter 21 arc sec Illumination 60% Elongation from Sun 46 degrees Fig. 1. Venus from Earth shows no obvious detail (click Fig. 1 to enlarge) although it is the closest approaching planet to Earth, coming as close as 0.27 AU or abt. 40 million km (25 million mi). [In comparision, Mars was further from Earth, abt. 0.37 AU or 56 million km (35 million mi) at its close approach to Earth during 2004 August.] However, images taken in the ultraviolet part of the spectrum often show show faint atmospheric markings. Otherwise, global cloud cover hides its surface from earthly eyes. (Nevertheless, astronomers can use radar imaging to map its solid surface.)
Venus resembles Earth more closely in size and mass than any other Solar System object. From Earth, the most significant and remarkable characteristic of Venus from Earth is its shape—Venus phases like the Moon! In March 2004 Venus appears in gibbous phase with its disk appearing about 60% illuminated.
In addition, the apparent size of Venus's disk changes dramatically as the planet approaches Earth. By May 2004 the disk will appear as a thin crescent but its diameter will grow nearly three times larger! Venus has no known natural satellites.
More Info About Venus (from The Nine Planets) Back to Top
JUPITER — Fifth Planet from Sun & Largest Planet
VIEW THROUGH TELESCOPE
(Moderate Magnification)
Move cursor over image to view annotation or click to enlarge 3xFAST FACTS
(For the Technically Minded)
Distance from Sun 5.2 times Earth Orbit Period Around Sun 11.8 years Diameter 11.5 times Earth Rotation Period 9.8 hours (retrograde) Mass 318 times Earth Density 1.3 x water Bulk Composition Outer gaseous;
interior liquid/metalic
hydrogen; core rock?Atmosphere Hydrogen (85%);
Helium (15%)
Mid-March 2004Distance from Earth 670 million km or
415 million miMagnitude -2.5 Angular Diameter 44 arc sec Elongation from Sun 165 degrees Fig. 2. Jupiter from Earth shows colored, exquisite cloud belts. The two equatorial belts are usually obvious; many others can sometimes be glimpsed. The polar regions are darker including the planet's edge (limb), a feature called limb darkening. Careful observers may spot the famous salmon colored "Red Spot" if on the Earth facing side.
Jupiter is not spherical but oblate. If magnified enough, the non spherical shape of Jupiter can be seen. (Click on Fig. 2.) Jupiter, largest planet in the Solar System, is often called a "gas giant" and has no solid surface like Earth. Instead, a thick atmosphere becomes very hot and dense at depth giving way to an interior of liquid and metallic hydrogen with a possible rocky core. Jupiter has as at least 63 satellites but only the four Galilean satellites are large and bright enough to be visible through small telescopes. Each appears as a bright "star": Io (I), Europa (II), Ganymede (III) and Callisto (IV). They nearly align with the planet's equator.
These four satellites, discovered by Galileo (1601), are very easy to spot in small telescopes. Sometimes fewer are seen if one or more is in Jupiter's shadow or crossing in front of the planet. At this time the satellite's shadow is often apparent on Jupiter's disk. Io and Europa have diameters similar to the Moon while the other two have diameters similar to Mercury. Orbit periods range from 1.8 days (Io) to 16.7 days (Callisto). Use the Sky &Telescope articles below to calculate satellite positions and transit time of the Great Red Spot.
Back to Top
SATURN — Sixth Planet from Sun & Second Largest Planet
VIEW THROUGH TELESCOPE
(Moderate Magnification)
Move cursor over image to view annotation or click to enlarge 3xFAST FACTS
(For the Technically Minded)
Distance from Sun 9.6 times Earth Orbit Period Around Sun 29.6 years Diameter 9.4 times Earth Rotation Period 10.6 hours (retrograde) Mass 95 times Earth Density 0.7 x water Bulk Composition Outer gaseous;
interior liquid/metalic
hydrogen; core rock?Atmosphere Hydrogen (94%);
Helium (6%)
Mid-March 2004Distance from Earth 1,320 million km or
820 million miMagnitude +0.6 Angular Diameter 19 arc sec/rings 42 arc sec Elongation from Sun 100 degrees Fig. 3. Saturn, the ringed planet, presents an almost 3-D view that is unequaled among celestial objects. Like Jupiter, Saturn is a "gas giant" and has no solid surface like Earth. This planet shows fainter and fewer cloud belts from Earth than Jupiter with only a hint of color. However, Saturn's rings are breathtakingly open (tilt is 25 degrees toward Earth) in 2004 allowing an optimum view of the southern hemisphere and south face of the rings.
The rings are easily seen in small telescopes and larger scopes easily show the planet–ring gap. (Click on Fig. 3.) In fact, the rings of Saturn are multiple. (Thousands can be seen in Voyager spacecraft images.) Careful observers may spot Cassini's division, most easily seen at either end of the rings. Observers need good skies and a quality telescope to trace the division around the rings. Other divisions are much more difficult.
Furthermore depending on the Sun angle, the shadow of the planet on the rings or the shadow of the rings on the planet may be visible. Saturn is also clearly not spherical. Like Jupiter, the edge (limb) of this planet is limb darkened with also darker polar regions.
Saturn has as at least 31 satellites, less than Jupiter. However, occasionally more Saturnian satellites can be seen than Jovian satellites! Saturn's large satellite Titan (VI), nearly 15% larger than Mercury, is usually obvious as a conspicuous "star." In addition, several faint satellites may be visible although the glare of Saturn can make them difficult to see: Rhea (V), Tethys (III), Dione (IV) and faint Enceladus (II). (The latter satellite is especially difficult to spot.) Unlike Jupiter, the tilt of Saturn to Earth causes its satellites to appear scattered around the planet. Except for bright Titan, a chart or map of the satellite positions is usually needed to identify each. Use the Sky & Telescope article below to calculate the positions of Saturnian satellites.
- An Observing Guide to Saturn (from Sky & Telescope)
- Saturn's Moons in 2004 (from Sky & Telescope)
– incl. utility to identify satellitesBack to Top
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