|
|
The Earth's solar system is made up of the sun and the bodies that orbit around it.
These bodies include eight planets and more than 70 known moons, asteroids, comets and meteoroids, as well as interplanetary dust and gases.
I
magine a stick going through the Earth from pole to pole. This is the axis. Each planet rotates, or spins,
around its axis. The time it takes to complete one rotation is
one day. Each planet also orbits the sun, that is, it follows
a set path to go around the sun. The time a planet takes to complete
one orbit is called a year.
Information about the Planets in their order from the sun
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Mercury | 4,850 | 58,000,000 | 88 days | 58 days,
16 hours |
 NOTES: Dry, extremely hot. Surface full of craters. To astronomers in Ancient Greece this planet was known as Apollo when seen in the morning, and Hermes when seen in the evening. The planet was later named Mercury after the Roman messenger God. The American spacecraft, Mariner 10, flew by the planet three times in 1974 and 1975. About 45 percent of the surface has been mapped. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Venus | 12,100 | 108,000,000 | 225 days | 243 days |
 NOTES: Surrounded by orange clouds of
poisonous gas the planet is a burning desert environment. Ancient
Greek astronomers called this planet Hesperus when it was seen
in the morning, and Phosphorus when seen in the evening. The
Romans named it Venus after the goddess of love. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Earth | 12,750 | 150,000,000 | 365 days | 23 hours, 56 minutes | 1 |
 NOTES: The only known inhabited planet, believed to be about 4000 million years old. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Mars | 6,880 | 228,000,000 | 687 days | 24 hours, 37 minutes | 2 |
 NOTES: Known as the Red Planet, surface is a cold desert. Has no oceans. Has same land area as Earth. Mars is named after the Roman god of war. Its two moons are named after the horses, said to pull the god's chariot, Phobos and Deimos. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Jupiter | 143,000 | 778,000,000 | 12 years | 9 hours, 50 minutes | 39 |
 NOTES: Largest planet in our solar system. Consists of gas & liquid. Has a ring around it too dark to be seen from Earth. Astronomers in Ancient Rome named the planet after the ruler of all Roman gods. Jupiter's rings were discovered by the Voyager-1 space probe in 1979. The four largest moons are Io, Europa, Ganymede and Callisto. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Saturn | 120,000 | 1,425,000,000 | 30 years | 10 hours, 14 minutes | 24 |
 NOTES: Saturn has 18 named satellites plus 12 recently discovered and as yet unnamed ones. The largest of its satellites (moons) is called Titan.Tethys (named after a Greek sea goddess) and Dione (a daughter of Zeus) Mimas, and Enceladus (son of the god Titan) are the names of four of Saturn's other moons. The planet was named in the 6th century after the Roman god of agriculture. First observed with a telescope by Galileo in 1610. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Uranus | 51,000 | 2,687,000,000 | 84 years | 20 hours ( approx) | 21 |
 NOTES: Surrounded by clouds of blue green gas. Has 10 rings made up of dust particles. Tilts at angle, probably because of comet crashing into it. The rings adjusted their orbit and travel over and under instead of around equator. This planet was discovered by Sir william Herschell in 1781. The first of the rings were discovered in 1977. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Neptune | 50,000 | 4,495,000,000 | 165 years | 21 hours (approx) | 8 |
 NOTES: Powder blue colour, has 5 rings and at least 8 moons. Ancient astronomers calculated that there must be a planet exisiting in that place and the Romans named it after their god of the sea. It wasn't actually discovered until 1846. Voyager 2, an unmanned robot space probe photographed the five rings surrounding Neptune in 1989. |
| Planet | Diameter (kms) |
Kms from the sun |
Time to orbit sun | 1 Rotation (length of a day) |
No of Moons |
| Pluto | 2,500 | 5,890,000,000 | 248 years | 6 days, 9 hours | 3 |
|
Two of Pluto's moons were discovered by the Hubble Space Telescope in May 2005. |
| Want to remember the names and the order of the planets? A mnemonic device is one way to help you remember the names of the planets in order from the Sun. Here's one that uses the first letters of words in a phrase. My Very Excellent Mother Just Served Us Nachos : Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune |
For another kidcyber page about planets go here
Another good site is: http://www.dustbunny.com/afk/planets/
Go here to read more information about the planets and the solar system
If you use any part of this in your own work, acknowledge this source in your bibliography like this:
Thomas, R. & Sydenham, S. Planets [Online] www.kidcyber.com.au (2005)
updated March 2009 © www.kidcyber.com.au
NOTES: Smaller than Earth's moon. Astronomer
Percival Lowell predicted its existence in 1916. Systematic searching
followed and it was finally found by American amateur astronomer
Clyde Tombaugh in 1930. The astonomical sign for the planet is
made up of Lowell's initials, and so the planet was named Pluto.