<p> Chapter 27 – The Planets and the Solar System I. The Inner Planets A. Two Planetary Neighborhoods 1. Inner Planets – Mercury, Venus, ______, Mars a. All have ______crust b. Dense mantle layers and ______c. Because of their Earth like appearance they are also known as ______planets 2. Outer Planets – Jupiter, Saturn, Uranus, Neptune and Pluto a. 1st four are called ______– or ______like b. very large gaseous planets with ______crust c. low ______due to size d. have ______systems e. Pluto is an oddball – not ______enough to be terrestrial; too ______to be Jovian B. Mercury 1. Nearest to the Sun 2. Orbits the sun in ______days 3. ______of terrestrials 4. Mercury surface resembles the ______5. Rotates every ______6. ______– day 400°C; night –200°C C. Venus – ______Sister Planet – 2nd planet from the Sun 1. Near each other similar in diameter, mass and ______2. Venus is the only planet to ______from east to west 3. ______every 243 days 4. Orbits every ______days 5. Thick yellow clouds make surface impossible to see 6. ______radar mapped it 7. ______system 8. Yellow clouds made of ______acid 9. Surface is hot due to ______effect (CO2) causing surface to be ______°C 10. Visible from Earth in the morning or early ______– “evening star” D. Mars – ______planet from the Sun 1. 687 day orbit 2. Axis tilted about the same as earth’s giving it ______. However they are 2 times as long 3. Very thin atmosphere (1% of Earth’s) mostly ______4. Has ice caps – thought to be ______covered by frozen ______5. Spacecraft have photographed and landed on Mars surface 6. Largest known ______in the solar system “Olympus Mons” 7. Has a valley system suggesting ______once ran on its surface 8. Page 543, 5 Martian landings II. Outer Planets A. ______Planets – Jupiter, Saturn, Uranus and Neptune 1. Much ______than terrestrials – smallest, Uranus, is 15 times more massive than earth 2. No ______surfaces – their “surface” is an uppermost gas layer 3. Composed mainly of light elements _____ and _____ All Jovian planets have ring systems B. Jupiter – 5th Planet from the Sun 1. ______year orbit 2. 10 hour rotation 3. has ______more mass than all the other planets combined 4. radiates 2 times as much energy back into space as it receives from the ______5. Galileo probe entered Jupiter’s atmosphere in 1995 – found no thick ______and higher than expected temperatures C. Saturn – 6th planet from the Sun 1. ______year orbit 2. 10 hour ______3. lowest density of all planets, less than ______4. Saturn also radiates ______than it receives from the sun, like Jupiter it has internal heat sources D. Uranus – 7th planet from the sun 1. ______year orbit 2. 17.2 hour ______3. it’s rotational axis is ______almost completely over 4. It’s magnetic field is ______E. Neptune – 8th planet (most of the time) 1. ______year orbit 2. ______16.1 hours 3. Neptune was found after astronomers predicted its location ______in 1846 4. Winds over 2000 km/hr 5. Becomes the 9th planet when Pluto is taken close to the Sun due to Pluto’s highly ______orbit F. Pluto 1. ______year orbit 2. smallest planet in the ______3. Its moon, Charon, is ______its size 4. Most of its atmosphere is frozen. However, it ______slightly when it nears the sun III. Planetary Satellites (moons) A. Satellites of Earth and Mars 1. Earth has one ______2. Mars has 2 tiny moons, ______and Phobos 3. Phobos circles mars ______times a day 4. ______and ______have no satellites B. Jupiter’s Moons 1. At least ______2. Galilean moons – Io, Europa, Ganymede and Callisto are the 4 largest discovered by ______3. Io is geologically active a. ______active volcanoes b. No signs of ______impacts c. Galileo spacecraft found it has an ______core surrounded by a molten ______rock d. Heat on ______is caused by tidal forces from Jupiter 4. Europa a. Surface is thought to be frozen ______b. It is thought liquid water may exist under the______5. Ganymede – the ______a. Larger than Pluto and ______b. Surface of ______6. Callisto – most heavily ______object in the solar system C. Saturn’s Moons 1. At least ______moons 2. Largest is ______a. Only moon in solar system to have a substantial ______D. Uranus’s Moons 1. At least ______2. 5 major moons are Titania, Oberon, Umbriel, Ariel, and ______a. all lack atmosphere and are heavily cratered E. Neptune’s Moons 1. At least 13 moons – Triton is the largest IV. Solar System Debris A. Comets and TNOs (Trans ______Objects) 1. Comets described as dirty snowballs a. Spend most of their time beyond the ______of Neptune b. Do not become visible until they travel inside ______orbit c. Has 2 parts, ______and tail d. Tail always points ______from the sun due to solar winds e. Most famous comet is ______, it appears once every 76 years – last visit ______B. Asteroids – solid rocklike masses 1. Uneven surface causes their ______to change 2. Revolve same direction as ______3. Most in asteroid belt between Mars and ______C. Meteors and Meteoroids 1. ______– rock or ice fragment traveling in space, they differ from asteroids in that they are smaller in ______2. ______– when a meteoroid enters earth’s atmosphere and burns up “shooting star” 3. Meteor shower – occurs when earth passes into debris left by a ______that crossed earth’s path – very predictable, named after the ______in the background. D. Meteorite 1. A large meteoroid that survives earth’s ______and strikes its surface 2. 3 types a. ______– resemble earth’s rocks, mostly made of silicates  95% b. ______– mostly iron  5% c. ______irons  <1% 3. Most found in the ice of ______E. Impact Craters – bowl shaped depressions that remain after a meteor or other object strikes ______1. ______on earth because a. The ______burns up most meteoroids b. ______is geologically active 2. Best known is Barringer ______in AZ</p>