1. The Solar System Review

2. Sun -The sun is known to be the most complex star in our solar system - It is believed that the sun only has 5 billion years left - Once the sun has exhausted all of its hydrogen fuel, it is said that it will no longer be able to withstand gravitational contraction.

3. Mercury -Mercury is the closest planet to the sun -This planet resembles the Earth’s moon and appears to have a crust of light silicate rock like the Earth -Mercury bakes in the daylight and freezes at night - One Mercury year is equal to 88 Earth days -Mercury spins at a rate of 10 kilometers (6 miles) per hour

4. Venus -Most nearly resembles Earth in its size, physical composition and density compared to any other planet - Venus’ surface temperature reaches 900 degrees Fahrenheit, hot enough to melt lead - Mariner 2 and Mariner 5 discovered two continent like high areas, on about ½ the size of Africa and the other the size of Australia. - There is evidence of 2 major volcanic areas -The predominant weather pattern for Venus is a high speed circulation of clouds, that are made up of sulfuric acid - One Venus year is equal to 224.7 Earth days

5. Earth -Earth’s atmosphere is composed of 78% nitrogen and 21% oxygen. - Earth is the only known planet to harbor life. - The Earth circles at a distance of 93 million miles, is the third planet from the sun, and is the fifth largest planet in the solar system. - One Earth year is 365.3 Earth days -Earth’s rapid spin and nickel-iron core produce an extensive magnetic field. Coupled with the atmosphere, this shields us from nearly all harmful radiation from the sun and other stars

6. Mars -Mars has been considered the solar system’s primary candidate for harboring extraterrestrial life -The atmosphere is much like Venus in that it is composed primarily of carbon dioxide, with small percentages of nitrogen, oxygen, and argon, with trace amounts of krypton and xenon. - Physical features on Mars resemble shorelines, gorges, riverbeds, and islands, suggesting that great rivers once existed on the planet -Mars has two moons, Phobos and Deimos. -One Mars year is 687 Earth days

7. Jupiter - Jupiter has been found to be a whirling ball of liquid hydrogen with a unique atmosphere that is mostly hydrogen and helium. - The Great Red Spot is a huge atmospheric storm, similar to a hurricane, that rotates counterclockwise. - Jupiter is the largest planet in the solar system. - One Jupiter year is equal to 11.86 earth years. -Jupiter has 16 moons

8. Saturn -Saturn is composed mostly of hydrogen -Saturn is surrounded by thousands of ringlets that encircle the planet. - Most of the particles that surround the planet are ice and frosted rock -One Saturn year is equal to 29.46 Earth years -Saturn has 18 moons. -One rotation period around the sun takes 10 hours and 40 minutes

9. Uranus/ Neptune -Uranus and Neptune are very similar in their atmosphere and climate. -The atmosphere of both of these planets contains mostly methane which gives this planet its greenish color. Traces of hydrogen and helium are also present. - Uranus is known to have 15 moons. -Neptune is known to have only 8 moons

10. REVIEW QUESTIONS

11. Which planet is the largest planet in our solar system? a)JupiterJupiter b)MarsMars c)EarthEarth d)The SunThe Sun

14. _______ gives Neptune and Uranus its greenish color? a)HydrogenHydrogen b)HeliumHelium c)MethaneMethane d)OxygenOxygen

15. There is evidence of two major volcanic areas on which planet? a)MarsMars b)JupiterJupiter c)EarthEarth d)VenusVenus

16. Saturn’s rings are composed of materials that are mostly ______. a)RockRock b)Dust and bouldersDust and boulders c)Ice and frosted rockIce and frosted rock d)Liquid hydrogenLiquid hydrogen

17. Mars has 2 moons. What are their names? a)Phineas and FerbPhineas and Ferb b)Phobos and DeimosPhobos and Deimos c)Rocky and BullwinkleRocky and Bullwinkle d)Bill and YogiBill and Yogi