Section 2 Inner Planets Terrestrial vs Jovian Classifying

Section 2: Inner Planets

• Terrestrial vs. Jovian: Classifying Planets • Terrestrial-like Earth: Mercury, Venus, Earth and Mars. • Jovian-huge gas planets: Jupiter, Saturn, Uranus, and Neptune. • Inner vs. Outer: • Inner-found before the asteroid belt: Mercury, Venus, Earth, and Mars. • Outer-found after the asteroid belt: Jupiter, Saturn, Uranus, and Neptune. • Inferior vs. Superior: • Inferior-between the Sun and Earth: Mercury and Venus. • Superior-after Earth: Mars, Jupiter, Saturn, Uranus, and Neptune.

• Named after the Roman Fleet Footed God • The smallest planet • Closest to the Sun • Heavily cratered • Large iron core (70% of Mercury’s volume) • No atmosphere • 427 (800 F) to -127 ºC (-197 F) • The year is only 88 days • Spins the slowest on its axis, but it revolves the fastest around the sun Mercury

• 2 nd from Sun • Thick atmosphere of Carbon Dioxide- runaway greenhouse effect • Shines the brightest in our night sky • Most volcanoes in solar system of the planets • Spins backwards • Up to 900 ºF • Named after the Roman goddess of beauty and love- often called Earth’s twin • Clouds of sulfuric acid • Magellan, Cassini Huygens and MESSENGER have all flown by Venus

Earth • Earth: 3 rd from Sun • Temperatures perfect for water in solid, liquid, and gas states. • Has ozone to protect from the Sun’s harmful radiation. • 70% water, 30% land

• 4 th from Sun • ½ the size of Earth • Red planet- from rusted iron in crust. • Has frozen water under ice caps • Largest volcano- Olympus Mons • Largest Canyon- Valles Marineris • 2 moons: Phobos (fear) and Deimos (flight) • Cold: -100 ºC night, just above freezing during day (-148 F) • Named after Roman God of War • 24. 5 hour day • Has seasons like Earth Mars

NASA on Mars • The Mariner 9 • Viking 1 and Viking 2 • Global Surveyor • Mars Odyssey • Spirit and Opportunity Land Rovers • Mars Pathfinder

Section 3: Outer Planets

• 5 th from the Sun • Largest planet (1, 323 Earths) • Named after Roman God of all Gods • Mostly hydrogen and helium • The Great Red Spot- a approx. 400 year old hurricane big enough to hold 2 -3 Earths. • Spins fastest on its axis • Has lightning in clouds • Has 50 named moons and 14 other moons not named • Has 3 rings of dust • Studied by Galileo space probe Jupiter

Jupiter’s 4 Big Moons • 4 huge “Galilean Moons”: • Io: most volcanically active body in solar system. • Europa: mostly rock with a thick, cracked but smooth crust of ice; deep, warm ocean that holds twice as much water as Earth’s oceans. • Ganymede: Larger than Mercury, most likely had a volcanic past. Likely to have an ocean. • Callisto: Cratered and most likely covered in a salty ocean.

• 6 th from Sun • Second largest planet (752 Earths) • Named after Roman Lord of the Rings • Mostly hydrogen and helium • It’s low density would allow it to float in water • Known as the ringed planet- has largest and most complex ring system • Made of ice and rock • 7 Rings A-G: Cassini division is the gap between rings Saturn

Saturn’s Moons • Saturn has over 30 moons. • The largest moon is Titan: • Larger than Mercury • Has areas of water ice • Has areas composed of hydrocarbonsorganic compounds that contain hydrogen and carbon. • All living things are made of carbon. • Scientists are interested in the possibility of life here.

• 7 th from the Sun • 3 rd largest (Fits only 64 Earths) • 27 moons • Mostly hydrogen, helium & 2% methane • Looks bluish-green in color • Tilted 98º- rotates on its side • 11 rings- dark and narrow • Father of Neptune and Jupiter • May have slushy water • 5 large moons- Miranda • This planet was discovered using mathnobody was even looking for it. Uranus

Neptune • 8 th from Sun • 4 th largest (58 Earths) • Has rings • Has at least 13 moons: Triton, the largest, has geysers that erupt methane and nitrogen • Has a Great Dark Spot “Wizard’s Eye” • Named after Roman God of the Sea • Similar atmosphere to Uranus, but more methane, so it looks even bluer.

Pluto • Farthest from the sun • It takes 248 years to orbit the sun • Now considered a dwarf planet • Named after the Roman God of the Underworld • Has 5 moons: the biggest one is named Charon which is about ½ the size of Pluto • Solid ice-rock surface

Comets , Asteroids, and Meteoroids • A comet, is composed of ice, dust and rock particles mixed with methane and ammonia. • Halley’s comet appears every 76 years. • It will appear again in 2061. • An asteroid is a rocky object formed from material similar to the planets- found in asteroid belts • A meteoroid is a rocky object formed from asteroids or comets. • If it burns up in our atmosphere it is a shooting star • When it hits Earth it is called a meteorite

• Sedna has been labeled a distant planetoid • It is smaller than Pluto, but bigger than a comet. • It is three times farther away from Earth than Pluto