Planets

1. Planets Janelle Mendiola

2. Mercury • Named after the messenger of the Roman Gods • Mercury is extremely dense and has no plate tectonics. • It has been visited by two spacecrafts; Mariner 10 in 1975 and 1975, and Messenger in 2004. • Its atmosphere is made of Carbon Dioxide, Nitrogen, and Argon • Facts: if you weigh 100 pounds in Earth, you’ll weigh 37 pounds in Mercury; it takes less than 88 Earth days for Mercury to orbit around the sun; it completes its rotation in 59 Earth days.

3. Venus • “Morning Star” named after the Roman Goddess of Love and Beauty. • Atmosphere made of Carbon Dioxide and Nitrogen • The first spacecraft to visit Venus was Mariner 2 in 1962 • Up to 100,000 volcanoes about 5 miles high • Facts: Venus has no moons, it’s the brightest object in the sky except for the Sun and the Moon, reaches up to 900 degrees.

4. Earth • Origin of the name came from Erda, the Anglo-Saxon word for “ground” or “soil.” The only planet not named for a figure of Greek or Roman mythology. • The study of the Earth can be studied without the aid of a spacecraft, in the 20th century maps were made of the entire planet. • Atmosphere made of Nitrogen and Oxygen • Facts: Earth’s the only planet in the Solar System to have water in its three states of matter. Earthquakes, volcanoes, and mountains are all formed by Earth’s moving plates. Earth’s continents were once all shaped together called Pangea.

5. Mars • “Red Planet” named after the Roman God of War. • Large canons, fierce windstorms that cover the whole planet • Made of Carbon Dioxide, Nitrogen, and Argon • No place for humans to live • Visited by Mariner 4, Mars 2, 2 Viking landers, Mars Pathfinder • Facts: Mars’ red color is due to iron oxide. Two moons. Mars has 37.5% of the gravity that Earth has.

6. Jupiter • “Wandering Star” named after the ruler of the Roman gods • Made of gas and liquid • Major feature: Great Red Spot, a giant spinning storm resembling a hurricane. • Been visited by 8 spacecrafts: Pioneer 10 & 11, Voyagers 1 & 2, Galileo, Ulysses, Cassini, and New Horizons • Facts: Jupiter is the largest planet in the solar system. Has the lowest density of all planets. Completely rotates around its axis in 10 hours

7. Saturn • Named after the Roman God of Agriculture • Atmosphere made of Hydrogen and Helium • Least dense of all the planets • Up to 60 moons • Pioneer 11, Voyagers 1 & 2, and Cassini-Huygens spacecraft have visited Saturn • Facts: Saturn rotates faster than any planet except Jupiter. Nine times bigger than Earth. Rings made of gas, rock, and ice.

8. Uranus • Named after the Roman God who was the father of the Titans • Atmosphere made of Hydrogen, Helium, and Methane • Coldest planet in the solar system, also known as the “Ice Planet” • Almost visible on Earth without a telescope • Visited by one spacecraft, Voyager 2, in 1986 • Facts: Uranus has 27 known satellites. Third largest planet. Sometimes rotates on its side.

9. Neptune • Named after the Roman God of the Sea • Made of Hydrogen, Helium, and Methane • Major feature: Great Dark Spot. A depression in the atmosphere surrounded by high cirrus clouds. • Visited by Voyager 2 in 1989 • Facts: has 8 known moons. Orbits around the sun once every 165 Earth years. Neptune is the stormiest planet.

10. Planet Requirements • The planet must dominate its area • Planet must orbit around the sun • Planet must also have enough gravity to keep in a spherical shape • Pluto was demoted because it failed all three of the requirements