Our Solar System There are 8 planets in the solar system. Pluto is no longer considered a planet. From the sun the order of the planets is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune Jupiter Jupiter is the largest planet. It is 5th from the sun. It is considered a gas giant. It has no solid surface. Saturn Saturn is 6th from the sun. It is considered a gas giant. It has no solid surface. It has rings around it. Uranus the 7th planet Uranus from the sun. It is considered a gas giant. It has no solid surface. It has rings around it. Neptune is the 8th planet from the sun. Neptune It appears blue from telescopes and is a gas giant. It has no solid surface. It has rings around it. Earth is the 3rd planet from the sun. Earth It is a terrestrial planet (rocky) It can support life because it has an atmosphere, liquid water and is close enough to the sun for light and warmth. Venus is second from the sun. It is similar to Venus the size of earth. It is a very hot planet. It is a terrestrial planet (rocky) Mars is 4th from the sun. Mars It is a terrestrial planet (rocky) The atmosphere is thin and it has canyons and riverbeds. Mercury is the closet to the sun and is the smallest. Mercury It is a terrestrial planet (rocky) It has lots of craters and looks like our moon. Planets sorted in order Planets According to Size of size from largest to smallest are: 1- Jupiter 2- Saturn 3-Uranus 4-Neptune 5-Earth 6-Venus 7-Mars 8-Mercury Rotation The Earth rotates on its axis every 24 hours. Revolution The Earth completes one revolution around the sun every 365 days. Seasons Due to the tilt on its axis, the Earth experiences seasons during its revolution around the sun. When the tilt is closer to the sun it is spring and summer. Farther we experience fall and winter. Sun-Earth-Moon relationship The Sun is a stationary star. Earth rotates on its axis and revolves around the sun. The moon rotates on its axis and revolves around Earth. Sun An average sized star. It is 4.6 billion years old. It is about 110 times bigger than the Earth. The Moon The moon is a small rocky satellite. It rotates on its axis and revolves around the Earth about once every 30 days. It is ¼ the size of Earth. It has no atmosphere or life, has very little water, and extreme temperatures. Phases of the Moon There are 8 phases of the moon and are based on the moons position to Earth and the sun. 1. New moon 2. Waxing crescent 3. First quarter (half) 4. Waxing gibbous 5. Full 6. Waning gibbous 7. Last quarter (half) 8. Waning crescent Aristotle Proposed that there were planets and the earth was at its center Central region composed of four elements-earth, air, fire, and water Greek Philosopher and Scientist Ptolemy Proposed that the Earth was the center of the universe Used math as a basis to defend his theory Believed that the earth did not move; rather other objects moved around the earth in a Greek Astronomer and Mathematician perfectly circular motion Viewed the solar system was centered around the Copernicus sun; Believed that the earth rotates on an axis and revolves around the sun Most people could not comprehend a “moving” earth and rejected his theory Polish Astronomer Disagreed with Ptolemy’s theory Galileo Argued Aristotle’s view Believed in Copernicus’ idea of a “sun-centered” universe. Italian Physicist and Astronomer Apollo Missions 1968 – 1971 NASA made several missions to the moon and gathered Astronauts Neil Armstrong, Buzz Aldrin, Michael Collin were information. We members of the Apollo 11 Mission. Armstrong and Aldrin walked learned a lot about on the moon. Collin maintained control of the mother ship. the moon from their missions and studies and the samples they collected. Gas Giants the 4 largest planets, made mostly of gas: Saturn, Jupiter, Uranus, Neptune Terrestrial Planets rocky inner planets: Mercury, Earth, Venus, Neptune .