太阳系的介绍欧美风模板.ppt

The Solar System Whats in Our Solar System? Inner and Outer Planets ? Inner Planets: – Mercury – Venus – Earth – Mars ? Outer Planets – Jupiter – Saturn – Uranus – Neptune – Pluto The Relative Size of the Planets in the Solar System The Sun The 9 Planets of the Solar System Characteristics of Small Rocky Planets ? They are made up mostly of rock and metal. ? They are very heavy. ? They move slowly in space. ? They have no rings and few moons (if any). ? They have a diameter of less than 13,000 km. Mercury ? Mercury has a revolution period of 88 days. Mercury has extreme temperature fluctuations, ranging from 800 ? F (daytime) to -270 ? F (nighttime). ? Even though it is the closest planet to the sun, Scientists believe there is ICE on Mercury! The ice is protected from the suns heat by crater shadows. Venus Earth Earths Moon Mars Pluto ? Pluto has only one moon and takes about 249 years to orbit the sun. ? Part of Plutos orbit passes inside that of Neptune, so at times Neptune is the planet farthest from the sun. ? Pluto was located and named in 1930, but today Pluto is no longer considered a planet. Characteristics of Gas Giants ? They are made up mostly of gases (primarily hydrogen helium). ? They are very light for their size. ? They move quickly in space. ? They have rings and many moons. ? They have a diameter of less than 48,000 km Jupiter ? Jupiter is the largest and most massive planet. ? Its diameter is 11 times bigger than that of the Earths. ? It takes about 12 years for Jupiter to orbit the sun. ? Jupiter has 16 known moons.