Planets
This is some statistical information about the nine planets in our solar system. The mean difference refers to the avrage distance a planet is from the sun. The length of the year is in relation to one year on Earth. The temperature is the average surface temperature of the planet. Composition refers to that of the planet itself. Known satellites are listed. The numbers are for others known, but not named.
| Planet | Diameter | Mean Distance | Year | Rotation Period |
Temperature |
| Mercury | 4,880 km (3,031 mi) |
58 x 106 km (36 x 106 mi) |
87.97 days | 58.65 days | 427°C to -127°C (801°F to -279°F) |
| Venus | 12,104 km (7,521 mi) |
108.2 x 106 km (36 x 106 mi) |
225 days | 243 days | 462°C (864°F) |
| Earth | 12,756 km (7,926 mi) |
15 x 106 km (93 x 106 mi) |
365.25 days | 23.934 hours | 14°C (57°F) |
| Mars | 6,796 km (4,223 mi) |
227.9 x 106 km (141.6 x 106 mi) |
687 days | 24.617 hours | 17°C to -143°C (63°F to -225°F) |
| Jupiter | 142,984 km (88,846 mi) |
778.4 x 106 km (483.6 x 106 mi) |
12 years | 9.917 hours | -157°C (-250°F) |
| Saturn | 120,536 km (120,536 mi) |
1,429.4 x 106 km (888.2 x 106 mi) |
29.5 years | 10.65 hours | -78°C (-288°F) |
| Uranus | 51,118 km (31,763 mi) |
2.9 x 109 km (1.8 x 109 mi) |
84 years | 17.133 hours | -216°C (-357°F) |
| Neptune | 49,500 km (30,800 mi) |
4,504.3 x 106 km (2,798.8 x 106 mi) |
165 years | 16.117 hours | -214°C (-353°F) |
| Pluto | 2,300 km (1,430 mi) |
5,900.1 x 106 km (3,666.2 x 106 mi) |
248 years | 6 days | -223°C to -233°C (-369°F to -387°F) |
| Planet | Atmosphere | Composition | Satellites |
| Mercury | Oxygen, sodium, hydrogen, helium | Iron core and silicate mantle | None |
| Venus | Carbon dioxide, nitrogen, water vapour, argon, carbon monoxide, neon, sulfur dixode | Iron/nickel core and silicate surface | None |
| Earth | Nitrogen, oxygen, argon, traces of other gases | Inner core of solid iron; core of liquid iron and sulphur; mantle of magnesium, iron, aluminum, silicon, oxygen; crust of rock | Moon |
| Mars | Carbon dioxide, nitrogen, argon, oxygen, carbon monoxide, neon, krypton, xenon, water vapour | Silicon, iron | Phobos, Deimos |
| Jupiter | Hydrogen, helium, methane, ammonia, carbon monoxide, acetylene, phosphine, water vapour | Hydrogen, helium, methane | Ganymede, Callisto, Io, Amalthea, Himalia, Europa, Carme, Metis, Andrastea, Thebe, Leda, Lysithea, Elara, Ananke, Pasiphae, Sinope, twenty-three others |
| Saturn | Hydrogen, helium, methane, ammonia, phosphine | Iron core, encased in ice, and topped with a deep layer of liquid nitrogen | Mimas, Hyperion, Enceladus, Tethys, Titan, Dione, Pan, Prometheus, Pandora, Epimetheus, Janus, Calypso, Telesto, Helene, Rhea, Iapatus, Phoebe, Atlas, four others |
| Uranus | Hydrogen, helium, methane | Hydrogen, helium, plus some heavier elements | Miranda, Ariel, Umbriel, Titania, Oberon, Puck, Rosalind, Belinda, Caliban, Sycorax, Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, four others |
| Neptune | Hydrogen, helium, methane, acetylene | Ice, rock, hydrogen, helium | Triton, Nereid, N1, N2, N3, N4, N5, N6 |
| Pluto | Methane, nitrogen, carbon monoxide | Rock, frozen methane | Charon |
The Movement of Earth
- The Earth is rotating on its axis at 1,100 km/h. This movement causes night and day.
- Earth orbits the Sun once a year at 108,000 km/h. This movement causes the seasons and the appearance of seasonal constellations.
- The Sun, with the rest of our solar system, is moving toward the star 99 Hercules at 900,000 km/h. This is caused by the Sun's orbit around the Milky Way.
- The Milky Way lies on the edge of the Virgo supercluster, which is being pulled toward the constellation Centaurus.
- The expansion of the universe carries the galaxy clusters away from each other more rapidly than the concentration of galaxies are pulling toward it.
The Rings of Saturn
They are composed of icy particles, mainly very tiny, but can be up to the siae of a mountain. Each particle has its own orbit around Saturn. The diameter is possibly 250,000 km. The thickness is about the same as a fifty-storey building. Because of the gravitational pull of the planet, the rings are located around its equator.
One theory says that the rings were formed from the debris when a comet collided with one of Saturn's satellites. Another theory says that two of the satellites collided, with the pieces bumping into each other until equilibrium was achieved.
