Space Lesson 1: Universe

Astronomers measure distances in the Solar System in astronomical units (AU). Earth is 1 AU from the sun. The table below shows information about the distances of the gas giant planets from the sun.
Which gas giant planet is about 10 times farther from the sun than Earth is?

• Jupiter
• Saturn
• Uranus
• Neptune

The bodies of space can be classified based on their relative sizes. Which of the following generally lists the bodies of space in order from smallest to largest?

• universe, moon, galaxy, solar system, star, planet
• star, galaxy, planet, moon, solar system, universe
• moon, planet, star, solar system, galaxy, universe
• galaxy, universe, moon, planet, star, solar system

A light-year (ly) is the distance light travels in one year. If a star is 218 ly away from Earth, how long does it take that star’s light to travel far enough to reach Earth?

• 218 min
• 218 hours
• 218 years
• 218 light years

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

• a journey from Earth to the moon
• A journey from Earth to the dwarf planet, pluto
• A journey from Earth to the the next closest star, Proxima Centauri
• A journey from Earth to the next closest galaxy, Andromeda

Scientists use the light-year to describe the relationships between bodies in space. What does a light-year measure?

• the distance that light can travel in one year
• the brightness of light traveling through space
• the number of years it takes light to travel to Earth
• the time it takes light to travel 1 million km

Which two objects in space are farthest apart?

• Earth and Pluto
• Sun and Proxima Centauri (next closest star)
• Earth and the moon
• the Milky Way galaxy and the Andromeda galaxy

What would be the best unit to describe how big the universe is?

• millions of kilometers
• millions of astronomical units (A.U.)
• millions of miles
• millions of light years (l.y.)