Ch 27 Review

Planets & the Solar System

• Name the inner planets

• Mercury• Venus• Earth• Mars

• What lies between the inner and outer planets?

• Asteroid belt

• Where is the largest volcano in the solar system located?

• Mars

• What is another name for the inner planets (as a group)?

• Why are they called that?

• Terrestrial planets• b/c they are Earth-like

• What are the characteristics of the outer planets?

• Considerably larger than Earth• gaseous, outer layer is mostly hydrogen gas– closer to center hydrogen is compressed into a hot

liquid• Much less dense than Earth• All have ring systems

• Why isn’t Pluto considered a planet anymore?

• Oddity of the solar system– Not dense enough to be considered “terrestrial”– Too small to be “Jovian”– Strange orbit

• What is the orbital period of Mars?

• 88 Earth days

• The largest moon in the solar system is _________.

• Ganymede (around Jupiter)

• What is the relationship between the distance of a planet from the sun and its orbital period? Why?

• The closer the planet is to the sun, the shorter its orbital period. As you go further away, the planet has a longer distance to travel and the sun’s gravity pulls on it less.

• Why does Mercury have so many craters?

• It lacks an atmosphere

• What is unique about Venus’ rotation?

• rotates from east to west (clockwise)

• How long is Venus’ period of rotation?

• 243 Earth days

• On which planet is a day longer than a year?

• Venus

• Which planets radiate more energy into space than they receive? Why?

• Jupiter and Saturn b/c they have sources of internal heat

• Name all of the planets that have rings.

• Jupiter, Saturn, Uranus, Neptune

• What does Pluto’s atmosphere seem to do when it is as perihelion?

• Thaw slightly.

• Which planet has seasons like Earth?

• Mars

• The Galielean moons, Io, Europa, Ganymede, & Callisto orbit _____________.

• Jupiter

• What are the characteristics of terrestrial planets?

•Rocky crusts•dense mantle layers• very dense cores

• What do we now consider Pluto?

• Dwarf planet

• What is the difference between a meteoroid, meteor, & meteorite?

• Meteoroid = in space• Meteor= moving through Earth’s atmosphere

(“shooting star”)• Meteorite= meteor that has reached Earth’s

surface

• Why does Mars have seasons?

• It’s tilted on it’s axis (like Earth)

• What is the difference between an asteroid and a meteor?

• Asteroids are bigger

• How long are seasons on Mars compared to on Earth? Why?

• Twice as long b/c a year is twice as long

• How was Neptune discovered?

• Using mathematics

• What is a satellite?

• an object that orbits a planet

• What are the parts of a comet?

• Nucleus• Coma & tail (only when “near” the sun)

• What are the two “planetary” neighborhoods that we can divide the planets into?

• Inner planets• Outer planets

• Phobos & Deimos are the moons that orbit ___________.

• Mars

• Why is Venus’ temperature so high?

• It has a dense atmosphere that is mostly carbon dioxide (CO2) “runaway” greenhouse effect

• How often can we see Haley’s comet?

• Every 76 years

• _________ is one of Saturn’s moon, and is the second largest moon in the solar system.

• Titan

• What is another name for the outer planets (as a group)?

• Jovian planets, Jupiter-like planets, gas giants

• What is so interesting/unique about Titan?

• Only moon known to have a substantial atmosphere

• Comets spend most of their time _____________________.

• Beyond Neptune’s orbit

• Triton is one of _________’s moons.

• Neptune

• What does solar wind do to a comet’s tail?

solar wind pushes coma far out into space, forming dramatic tails… generally point away from the sun

• What shape are asteroids? What does this cause as they rotate?

• Irregular, causes them to appear to be changing in brightness as they rotate

• What is the density of Saturn? Why is this special?

• 0.7 g/cm3 … it could float on water

• Asteroids revolve around _____________.

• The sun

• Meteor showers are named for ___________.

• the constellation from which they appear to originate (ex. Perseids, happen in Aug., appear to come from constellation Perseus)

• What is the mass of Neptune (if Earth’s mass = 1)?

• 17.151 (Earths)

• What are the 3 basic types of meteorites?

• Stony– ~94%

• Iron– ~5%

• Stony-iron– ~1%

• Bowl-shaped depressions that remain after meteor or other object hits Earth, other planet, moon are called _____________.

• Impact craters

• What is Pluto’s mean distance from the sun?

• 5,900 million kilometers

• Titania, Oberon, Umbriel, Ariel, & Miranda are the 5 major moons of _____________.

• Uranus

• Name the outer planets

• Jupiter• Saturn• Uranus• Neptune

• What is the equatorial diameter of Jupiter?

• 142,800 km

• Why might some planets lack craters or have few craters?

• Have an atmosphere, are geologically active (“erases” craters)

• How many moons does Venus have?

• 0