Astronomers use the light-year to describe the relationship between objects in space. For example, the Andromeda galaxy is 2.5 million ly from Earth. Which of the following units is most similar to the light-year?

• gram
• second
• kilometer
• degree Celsius

Which of the following units would you use to measure the solar system?

• Astronomical Units
• Light Years
• Kilometers
• Parsecs

Space exploration has advanced our knowledge of the universe. Which space journey would take the longest?

• a journey from the Earth to the sun
• a journey from the Earth to the moon
• a journey from the Earth to a star in the constellation Centaurus
• a journey from the Earth to the farthest planet in our solar system, Neptune

Which of the following correctly lists the objects of space in order from largest to smallest?

• universe, galaxy, star, planet
• universe, galaxy, planet, star
• galaxy, universe, star, planet
• galaxy, universe, planet, star

Which statement below most accurately describes our universe?     

• Thousands of stars around a black hole
• A system of planets and moons
• All of the billions of stars and galaxies
• All of the known galaxies

A galaxy contains stars, gas, and dust. This matter must be held together or the galaxy will break apart. What is responsible for holding the stars, gas, and dust together in a galaxy?

• Heat
• Light
• Gravity
• Friction

The diagram above represents the development of our universe from the time of the Big Bang until the present.  Letter A indicates two objects in space.  The present-day objects labeled A are best identified as                     

• Asteroid belts
• Terrestrial planets
• Spiral galaxies
• Eccentric comets

What is a large collection of stars held together by gravity?

• Solar System
• Star
• Galaxy
• Planet

What object is composed of gas and emits light?

• Planet
• Asteroid
• Star
• Universe

What galaxy do we live in? 

• The Milky Way Galaxy
• The Sombrero Galaxy
• The Andromeda Galaxy
• The Tadpole Galaxy