Galaxies
The Milky Way is a medium-size galaxy. How many stars are there in the Milky Way galaxy?
A thousands of stars
B tens of millions of stars
C hundreds of millions of stars
D hundreds of billions of stars
D hundreds of billions of stars
Venus and Mars are the two planets closest to Earth. Which of these statements about Venus and Mars is true?
A Their orbits are the same size.
B They both have a large solid core.
C Their surfaces are covered with water.
D They have the same number of moons.
B They both have a large solid core.
Which of these characteristics distinguishes the outer planets from the inner planets?
A The outer planets have many moons.
B The outer planets orbit in a different direction.
C The outer planets have higher densities.
D The outer planets have smaller diameters.
A The outer planets have many moons.
While looking at the sky one night, Bevan saw a streak of light. Bevan’s father told him that the light was produced by a small chunk of rock passing through Earth’s atmosphere.
Which of these terms best describes what Bevan saw?
A asteroid
B comet
C meteor
D meteorite
C meteor
Kashvi likes to look out the window at the moon. She observes that it seems to change every week. Which sentence best explains why this happens?
A The moon moves between Earth and the sun.
B The moon rotates only once in about a month.
C The same side of the moon always faces Earth.
D The amount of the lighted part of the moon that faces Earth changes.
D The amount of the lighted part of the moon that faces Earth changes.
Galaxies are composed of many different objects. What kind of objects make up most of the visible matter in a galaxy?
A asteroids
B dust
C planets
D stars
D stars
Ming is doing a project on planets in other solar systems. She learns about a planet, called Planet Z. Planet Z is very large, has a thick atmosphere, and has a low density. Which of these planets in our solar system is Planet Z most similar to?
A Earth
B Mars
C Mercury
D Saturn
D Saturn
Earth and Saturn are both planets orbiting the sun. Which of these other features do the two planets have in common?
A They have a thin atmosphere.
B They rotate about an axis.
C Their orbits are the same length.
D They have about the same mass.
B They rotate about an axis
Skylab was the first American space station. It was in orbit around Earth from 1973 to 1979. Which of these objects was Skylab most similar to?
A comet
B moon
C planet
D star
B moon
A fourth-grader in Florida is doing an experiment in her science class. At the same time, a fourth-grader in China is getting a good night's sleep. What is responsible for it being daytime in Florida while it is nighttime in China?
A Earth's rotation
B Earth's revolution
C moon's revolution
D Earth's path as it orbits the sun
A Earth's rotation
Earth is part of the Milky Way galaxy. How does the Milky Way appear in the night sky from Earth?
A a bright, narrow band of stars
B a small, very dim group of stars
C a large number of stars in a broad, spiral shape
D a large cloudy band of stars spreading across the sky
D a large cloudy band of stars spreading across the sky
Josleen divided some of the planets into two main groups. The table below shows how she grouped them.
Group 1 Group 2
Mercury Saturn
Mars Uranus
Venus Jupiter
Which of the following two categories did Josleen most likely use to group the planets?
A planets and dwarf planets
B with moons and without moons
C orbit the sun and orbit other bodies
D small diameters and large diameters
D small diameters and large diameters
The table below shows some of the characteristics of a planet.
Length of day 25 hr
Number of moons 2
Diameter 6,800 km
Color red
Which two characteristics would be most helpful for determining whether the planet is a gas giant or a rocky planet?
A length of day and color
B diameter and length of day
C color and number of moons
D number of moons and diameter
D number of moons and diameter
The diagram below shows a planet and the sun.
What does the arrow on the diagram show?
A how the planet rotates on its axis
B the gaseous nature of the planet
C why the planet has seasons
D how the planet revolves around the sun
A how the planet rotates on its axis
Star A and Star B give off the same amount of light. Nancy observes these two stars in the night sky. Star A looks brighter than star B. Which best explains why Nancy sees star A as brighter?
A Star A is larger than star B.
B Star A is cooler than star B.
C Star A is closer to Earth than star B.
D Star A is farther from Earth than star B
C Star A is closer to Earth than star B.
There are several different types of galaxies. How do scientists classify galaxies?
A by size
B by shape
C by temperature
D by number of stars
B by shape
All the planets in the solar system orbit the sun. What is the main difference between the orbits of the inner and outer planets?
A The inner planets travel a greater distance than the outer planets do.
B The inner planets have almost round orbits, and the outer planets do not.
C The outer planets rotate as they orbit the sun, and the inner planets do not.
D The outer planets’ orbits are longer than the inner planets’ orbits.
D The outer planets’ orbits are longer than the inner planets’ orbits.
Which feature is true for all inner planets?
A. They are made mostly of gas.
B. They have many moons and rings.
C. They are rocky and smaller than the outer planets.
D. They are colder than the outer planets.
C. They are rocky and smaller than the outer planets.
Until 2006, Pluto was considered the solar system’s ninth planet. Pluto is now classified as a dwarf planet. Which of these properties of Pluto explains why it is classified as a dwarf planet?
A It does not orbit the sun.
B It is too far from Earth.
C It is too small to be a planet.
D It has other bodies in its orbit.
D It has other bodies in its orbit.
See picture for question
B
What is a galaxy?
a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
Saturn, Uranus, and Neptune are known as Jovian planets because they are similar to Jupiter. Which of these characteristics do these three planets have in common with Jupiter?
A a large solid core
B well-defined rings
C a thick gaseous atmosphere
D a density greater than Earth’s density
C a thick gaseous atmosphere
Which statement describes a major difference between the inner and outer planets?
A. Only inner planets orbit the Sun.
B. Outer planets are much smaller.
C. Inner planets are rocky, while outer planets are mostly gas.
D. Outer planets have higher temperatures.
C. Inner planets are rocky, while outer planets are mostly gas.
Ganymede is a moon of Jupiter. It is larger than Mercury and has a metallic core similar to Earth’s core. Which of these statements best explains why Ganymede is classified as a moon rather than a planet?
A It is too large to be called a planet.
B It orbits Jupiter instead of the sun.
C Its properties are different from Jupiter.
D It is farther from the sun than Mercury.
B It orbits Jupiter instead of the sun.
Stars form patterns known as constellations. People on Earth have given the constellations names. The table below lists the constellations that can be seen throughout the year in the Northern Hemisphere and Southern Hemisphere.
Season Northern Hemisphere Southern Hemisphere
Winter Orion Scorpius
Spring Leo Pegasus
Summer Scorpius Orion
Fall Pegasus Leo
What can you conclude from this table?
A The constellations that appear depend on the time of night.
B The constellations that appear depend on the season of the year.
C Different constellations form the same pattern of stars in the sky.
D Some constellations appear only in the Northern Hemisphere and others appear only in the Southern Hemisphere.
B The constellations that appear depend on the season of the year.