Jovian planets have extremely different compositions than terrestrial planets, all (with the exception of Pluto) being giant, and have a compostion similar to the Sun's, consisting of mainly hydrogen. They are commonly known as the "Gas Giants".
Please remember that the measurements used on these pages are all approximate, meaning that they are not exact. In some cases, my sources differed, and if I have gotten something wrong, feel free to correct me. Just be sure to provide at least two sources to back yourself up. This is only for my own protection, so some jokester doesn't give me all screwed up measurements. Thanx!
**Note, the following abbreviations are used**
ED- Equatorial Diameter
DFS- Distance From Sun
PO- Period of (Revolution or Rotation)
ST- Surface Temperature
Mkm- million kilometers
Mm- million miles
**The following are definitions of words to make things clearer to the reader.**
Revolution- when a celestial body makes a complete orbit around another body of equal or larger proportions
Rotation- when a celestial body completely turns on a set of axis
Satellites- moons, or orbiting material
Day- a spacial day is defined as how long it takes from sunrise to sunrise
Retrograde- Clockwise rotation when veiwed from over the planet's Northern axis
Prograde- Counterclockwise rotation. All but Venus and Uranus rotate prograde.
Jupiter Facts
ED- 142,800 km (88, 679m)
DFS- 778.3 Mkm
PORevolution- 11.86 terrestrial years
PORotation- In Earth time, 9 hrs, 50 min, 30 sec
Satellites- 16:
Metis, Adrastea, Amalthea, Thebe, Io, Europa, Ganymede, Callisto, Leda, Himalia,
Lysithea, Elara, Ananke, Carme, Pasiphae, Sinope.
Io, Europa, Ganymeded, and Callisto are the four largest.
Other-
Jupiter is the largest of all the planets, larger and heavier than all of the other planets combined. Its ED is 11 times Earth's ED. Its volume is 100 times Earth's, and its mass is 318 times Earth's. Jupiter's density is extremely close to the Sun's, and in many ways the two are very alike, both being gaseous giants and both having high hydrogen levels. Jupiter has a thick atmosphere, and incredible gravity, letting the planet have a cloud cover of hundreds of miles deep. The dark and light, red and brown bands and spots seen on Jupiter's surface are in reality bands of multicolored clouds. The clouds are highly active, and transfer material to one another, and even disintegrate at times. The Great Red Spot, which is over 25,000 miles long, and is big enough to swallow the Earth whole, is in reality a long lasting storm. Weather is interally driven, being as Jupiter gives off twice as much heat from internal sources than is received from the Sun. The source of this extreme heat give off is heat remaining from the planet's formation. Jupiter is believe to be a failed star, not being massive enough to support nuclear fusion. Jupiter has no solid surface, but a gradual transition from gas in the atmosphere, to a liquid hydrogen surface. Jupiter has the strongest magnetic field in the Solar System 20,000 times Earth's own, due to the large amounts of frozen, metallic hydrogen. The field is maintained by electric currents inside the planet's surface.
Io- Io has an unscarred surface, but at least seven active volcanoes.
Europa- Europa has no craters, but is crosscut by many narrow, high, dirty ridges. One theory- Europa's surface is thick, and frozen, due to Europa having no atmosphere. Some scientists believe that underneath the crust is a liquid ocean hundreds of feet deep, which may even support life, if only microscopic. When the surface ice cracks, dirty water rushes up through it and freezes, forming the high ridges.
Ganymede- Ganymede is dotted with very large, ancient, ringed craters.
Callisto- Callisto has ten times as many craters as Ganymede.
Saturn Facts
ED- 120,000 km (74,520 m)
DFS- 1,507 Mkm (936.4 Mm)
PORevolution- 29.46 terrestrial years
PORotation- 10 hrs, 39.4 min in Earth time
Other-
Saturn is the second largest planet in the Solar System. It has the least of all of planetary densitys. Many features and inner structures are similar to Jupiter's. Saturn has a well known ring system consisting of seven rings and two divisions. The rings are believed to be made of small particles of water and ammonia ice. The main rings are made up of thousands of smaller rings call ringlets. Flybys of the rings show that they are thin, not being more than 150 meters thick.
Saturn's Rings
- Distance from center of Saturn to inner edge of ring
D : 42,000 m
C : 45,500 m
B : 57,300 m
Cassini division : 73,000 m
A : 75,200 m
Encke division : 83,000 m
F : 87,400 m
G : 106,000 m
E : 130,000 m
Saturn has thirty moons, thus far discovered. The largest is Titan, which may have oceans of methane and ethane, whose atmospheric pressure is 1.6 times Earth's. Mimas, Enceladis, Tethys, Dione, and Rhea are the next largest, which are mainly composed of ice with many craters. Saturn's moons also seem to serve another purpose, called sheparding satellites. For example, the orbits of two satellites, S13 and S14 orbit on each side of the F ring. Their gravity sweeps any stray particles back into the ring.
Satellites- Pan, Atlas, Prometheus, Pandora, Janus, Epimetheus, Mimas, Enceladus, Tethys, Telesto,
Calypso, Dione, Helene, Rhea, Titan, Hyperion, Iapetes, Pheobe, and twelve unnamed.
Uranus Facts
ED- 52,000 km (32,292 m)
DFS- 2,869 Mkm (1,801 Mm)
PORevolution- 84 Earth years
PORotation- For this one, I've got two different answers, both of which have been backed up. Does anyone know which of these are accepted by NASA? : 11/16.3 hrs
Satellites: (17) Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Puck, Miranda, Ariel, Umbriel, Titania, Oberon, Caliban, Sycorax
Other-
Uranus is barely visible to the naked eye, with a magnitutde of 5.5. It is half the size of Saturn, and orbits in a retrograde direction. Uranus' axis is tilted 98* to the orbital plane, so the planet knows no night or day. The northern and southern halves are pointed at the sun alternately every 42 years. Uranus also has 7-11 rings, though not as glamorous or as well known as Saturn's. Uranus has a greenish blue atmosphere due to trace amounts of methane in the air. Scientists theorize that Uranus is covered with water over 8,000 kms deep with a central rocky core roughly the size of Earth itself. Uranus has 17 satellites, two of whom are sheparding satellites to one of Uranus's rings.
Ariel, Miranda, Oberon ,Titania, and Umbriel are sixty percent frozen water and forty percent rock. Miranda has incredibly unique structures of rectangular and circular shapes not found anywhere else in the Solar System, leading scientists to believe it never completed the process in which heavier elements sink to form the core and lighter elements rise to form the crust and outer layers.
Neptune Facts
ED- 49,500 km
DFS- 4,496Mkm (2,795Mm)
PORevolution- 164.8 terrestrial years
PORotation- 16.11 hrs
Other-
Neptune is far enough away from the Earth, that, with a magnitutde of eight, it is invisible to the naked eye. However, it can be observed through use of binoculars. Neptune's rotational period corresponds directly to the rotational period of its core, a unique fact compare to the other planets. The cloud formations rotate slower with a period of eighteen hours near the equator. Neptune's atmosphere is composed mainly of hydrogen and helium, with a smaller amount of methane, and is blue tinted. Cloud formations and spots also form on its surface.
Satellites- (8)
Naiad, Thalassa, Despoina, Galatea, Larissa, Proteus, Triton, Nereid
Pluto Facts
ED- 2,430 km (1,500m)
AverageDFS- 5,900 Mkm (3,660 Mm)
PORevolution- 247.7 terrestrial years
PORotation- 6 days, 9 hrs terrestrial time
Other-
Pluto and Neptune's orbits intersect each other, but a collision isn't predicted any time soon. Pluto's orbit is 17* to the ecliptic, or plane, of the other orbits. Its orbit is also the most ovular. Pluto is the smallest and remotest of all the planets, and therefore not much is known about this planet, seeing as it takes it nearly 250 years to go around the Sun once. Pluto has one moon, called Charon, and Charon's rate of revolution is the same as Pluto's rate of rotation. The two occult (or eclipse) each other regularily. The fact that the rate of revolution of Charon is the same as Pluto's rate of rotation means that Charon is always above the same area on Pluto. This means that on the opposite side of Pluto, there is no moon, and the veiw, or phase, is always the same in the same spot night after night. Charon is 19,300 km (12,000m) from Pluto is has an ED of 1,180 km (730 m).
Planet X
Two reasons for the existance of a tenth planet:
When one planet has another planet orbiting behind it, this causes slight discrepancies in where the planet is predicted to be and where it actually is. Neptune has these discrepancies, and sure enough, Pluto orbited around the Sun behind Neptune. Pluto's orbit has also found to have these discrepancies, implying that there is a tenth planet outside of Pluto.
Some scientists believe that in order for the planets to orbit around the Sun so continuously, the combined weight of the planets must equal the wieght of the Sun. Before Pluto was discovered, this weight didn't add up. When Pluto WAS discovered, its expected weight was far, far less, and so scientists believe there must be another planet behind Pluto in order to equal this out.
