What would it take to live here

What is the primary purpose of the article?

• To explain the history of space exploration

• To describe why water is important in the search for life on Mars

• To compare Earth’s water cycle to Mars’ atmosphere

• To show how astronauts train for Mars missions

According to the article, why do scientists focus on finding water when exploring Mars?

• Water is the easiest element to detect from space

• Water is necessary to support life as we know it

• Water would make Mars suitable for farming

• Water can help cool down spacecraft

What evidence does the author give to support the idea that water once existed on Mars?

• Photographs show dry riverbeds and lake beds

• Astronauts found water while walking on Mars

• Scientists have observed rainfall on Mars

• Satellites have detected fish fossils on Mars

What is the meaning of the phrase “follow the water” as used in the article?

• Scientists are tracing rivers on Earth to understand Mars

• Scientists use water to power spacecraft

• Scientists believe water leads to clues about life

• Scientists are learning to live without water on Mars

Which sentence best summarizes the article?

• Water once existed on Mars, and finding its traces may help scientists discover signs of life.

• Space exploration requires astronauts to carry large amounts of water.

• Mars has more water than any other planet in the solar system.

• Mars' atmosphere makes it impossible for water to exist today.