Comets are bodies that are __________ that orbit __________.
|A)||ice and rock, the Sun|
|B)||helium gas, the Sun|
|C)||icy, each planet|
|D)||larger than Earth, Earth|
The eccentricity of a perfect circle is __________ and a very elongated ellipse is __________.
|B)||nearly zero, one|
|C)||zero, nearly one|
The inner four planets of our solar system are called the __________ planets and the next four are called the __________ planets.
|A)||terrestrial, gas giant|
|D)||gas giant, terrestrial|
The objects that eventually formed planets by colliding and merging are called __________.
Use the table to determine the largest terrestrial planet.
Use the table to determine the smallest gas giant planet.
What are Jupiter's moons composed of?
|A)||iron and ice|
|C)||hydrogen and helium|
|D)||rock and ice|
What does the eccentricity of a planet describe?
|A)||how rare or common it is|
|B)||the distance to another planet|
|C)||the shape of its orbit|
|D)||the speed of its rotation|
What causes Uranus' blue appearance?
|A)||the vast oceans|
|B)||surfuric acid in its atmosphere|
|C)||the ammonia ice droplets|
|D)||the methane in its atmosphere|
What explains why the Sun governs the motion of all planets in our solar system?
|A)||the law of universal gravitation|
|B)||Kepler's third law|
|C)||retrograde motion of planets|
|D)||telescopic observations of the planets|
What is Olympus Mons?
|A)||a scarp on Mercury|
|B)||a composite volcano on Venus|
|C)||a large shield volcano on Mars|
|D)||one of Mars' moons|
Which describes the average distance between the Sun and Earth?
|A)||1 astronomical unit|
|D)||1 light year|
What shape describes the orbits of the planets?
Why do astronomers think that liquid water once existed on Mars?
|A)||evidence of once living plants and animals|
|B)||dried river and lake beds|
|C)||minerals that precipitated from evaporating water|
|D)||the red color of the planet's surface|
Where are most asteroids located?
|A)||orbiting all planets|
|B)||between Mars and Jupiter|
|C)||outside of Pluto's orbit|
|D)||between Earth and Venus|
Which space objects are similar in composition to the Sun?
|A)||Mercury, Venus, Mars|
|B)||Mercury, Io, Phoebe|
|C)||Venus, Mars, Jupiter,|
|D)||Jupiter, Saturn, Uranus|
Which group represents a collection of space objects with solid surfaces?
|A)||the Sun, Jupiter, Saturn, Uranus|
|B)||the Sun, Mercury, Venus, Saturn|
|C)||Mercury, Venus, Earth, Mars|
|D)||Jupiter, Saturn, Uranus, Pluto|
Why can't astronomers directly observe the surface of Venus without landing probes on the surface?
|A)||The surface is covered by thick clouds.|
|B)||Venus has a high albedo.|
|C)||Venus has a clockwise spin.|
|D)||The surface is covered by thick ice sheets.|
Why does Jupiter have a banded appearance?
|A)||due to it's four moons|
|C)||the Great Red Spot causes the bands|
|D)||flow patterns in its atmosphere|
In which direction is the tail of this comet pointing?
|A)||in the direction of the comet's orbit|
|B)||opposite the orbit direction|
|C)||toward the Sun|
|D)||away from the Sun|
The figure illustrates Kepler's second law. Which conclusion can you draw from analyzing the purple areas “swept out” by the planet each month?
|A)||The Sun is the center of the universe.|
|B)||The shape of a planet's orbit is an ellipse.|
|C)||Planets move faster when they are closer to the Sun and slower when they are farther away.|
|D)||The speed of a planet's orbit steadily increases as it moves around the Sun.|
Which requirement distinguishes a planet from a dwarf planet?
|A)||nearly spherical in shape|
|B)||orbits the Sun|
|C)||is not a satellite|
|D)||has no debris within its orbit|
Most comets in the solar system are positioned in the _____.