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 (CO 2 ) “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/cm 3 … 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)?
(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?
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