People have always known about space, even if what they knew wasn’t correct. Cave men uest to write things on the cave walls such as maps, and guides to the skies.
*There are 9 planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
*If you have any questions on words and their meanings, you can post them on the comments section for this page, and I will answer them soon as possible.
* The asteroid belt is between Mars and Jupiter.
About 2,000 years back, there lived an astronomer named Ptolemy, (Tah-uh-mee). An Astronomer,(Astr-on-em-er) is someone who studies space. An Astronaut is someone who goes into space. Ptolemy studied space for a long time, but no matter how long he studied he was wrong. Ptolemy believed the Earth was the center of everything, and that objects orbited the earth. He did not know the planets moons and asteroids orbited the sun.
Probably about 1,400 years after Ptolemy, there was an astronomer named Nicholas Copernicus, (Cuh-pur-kus). Nicholas studied Ptolemy’s ideas for sometime and he knew something sounded odd. Nicholas figured out that the planets, moons, and asteroids orbited the sun. Nicholas was afraid to tell people what he believed, because he they wouldn’t believe him.
Another astronomer was named Galileo Galilei, (Gal-ee-lie-y). He lived from 1564-1642. Galileo was from Italy. Many people admire Galileo for his use of the telescope. After All, he was the first astronomer to use a telescope to study stars and planets. Galileo learned more about the planets than Ptolemy and Nicholas did. He discovered 4 of Jupiter’s moons, and that Saturn has rings. Galileo learned a loy about gravity which is invisible force that holds us down to the ground.
In the 1700′s, there were only 6 planets that were know about by humans, Mercury, Venus, Earth, Mars, Jupiter and Saturn. In 1781, an English astronomer Sir William Herschel, (Her-shell) was looking at stars with his telescope. He spotted a little green dot that didn’t twinkle. William had discovered the 7th planet that was later named Uranus. There was something unusual about Uranus. It tiled on it’s side while it orbited the sun. Scientists started looking for an 8th planet beyond Uranus that could be pulling on Uranus. Astronomers searched for an 8th planet, and finally one was found. It was named Neptune.
Later after Neptune, people began to wonder about a 9th planet. Then another astronomer, Percival (Per-siv-all) Lowell, who built Lowell observatory in Arizona 1894, was the leader of the search. Lowell was famous for being an expert on Mars. His observatory began a search in 1905. Lowell lead the search until he died in 1916. Because of his death, the search came to an end for 13 years.
Finally in 1929, an astronomer named Clyde W. Tombaugh started the search again. Clyde was then the new leader of the 9th planet search. He was born in Illinois 1906 and was only 23 years old when he continued the search; that’s young compared to most astronomers. Clyde had not yet been to college, but knew a lot about space and telescopes.
Clyde used a special telescope on his project, and worked a very long time. Some people thought Clyde was wasting his time. He knew there was another planet up there, so he just called it planet X. In science, X means unknown.
In the afternoon of February 18, 1930, Clyde was looking back at some sky pictures that were taken in January. He noticed a dim object that looked like it could be the 9thplanet! Leaping with joy, Tombaugh ran back into the Lowell observatory and shouted, “I have found planet X!” This news spread through outhe world. People began thinking of names for planet X. Then an 11 year old English girl came up with Pluto. Her name was Venetia Burney. Pluto was the Greek and Roman name of the dead. He ruled the dark and coldness. The Lowell observatory loved the name Pluto, because planet X is a dark, cold planet far away from the sun. So that’s how Pluto was discovered and how it got it’s name.
How long does it take?
Planet Earth days/months/years
Mercury 88 Earth days
Venus 7 1/2 Earth months
Earth 365 days
Mars 23 Earth months
Jupiter 12 Earth years
Saturn 29 1/2 Earth years
Uranus 84 Earth years
Neptune 165 Earth years
Pluto 248 Earth years
* In 2015 the Horizon, (a rocket) will be launched to Pluto and bring back information to Earth.
* A Gas Giant is a planet that is made of gas. A Rockey planet is a planet that is made of rock. The Gas Giants are Jupiter, Saturn, Uranus and Neptune. Mercury, Venus, Earth and Mars. Pluto is in it’s own category; Ice planets. Pluto is made up of ice, and a teeny bit of rock. Pluto is not considered a Rocky planet because Rocky planets are closer to the sun, and Pluto is really far away from the sun.
