Contents CHAPTER 1 Floating Among the Stars CHAPTER 2 Out of This World CHAPTER 3 Permanent Settlements CHAPTER 4 Destination Mars CHAPTER 5 Beyond the Red Planet CHAPTER 6 What’s Next ACTIVITY Your Space Science Mission Glossary Learning More Index and About the Author 4 10 20 28 34 40 44 46 47 48
CHAPTER 1 Floating Among the Stars Can you imagine living on another world What would it be like to wake up and see the landscape of Mars from your bedroom window How would it feel to float above the clouds of Venus What would it be like to live on a space station in orbit around Earth For centuries people have imagined traveling into space Today astronomers scientists who study space are asking themselves whether this might be possible What would it take for humans to live in space Scientists have been considering the question ever since astronomers first realized Earth was a planet orbiting the Sun As technology developed scientists began figuring out how to leave Earth In the later part of the 20th century people used airplanes to fly toward the very edge of space They learned that space is very different from the surface of our planet Space begins at the top of Earth s atmosphere which is the envelope of gases that surrounds a planet 4
The Race to Space Starting in the second half of the 20th century many scientists took up the challenge of getting people into space Engineers worked to build rockets and other spacecraft that could leave Earth’s atmosphere and safely return Astrophysicists study the behavior of bodies in space They figured out how space objects move in relation to one another and how to send spaceships between two moving planets Astrobiologists are scientists who study life on Earth and potential life elsewhere They wondered what life might be like on other planets and what humans would have to do to make it possible to live on other worlds This illustration imagines living underground as a way to cope with difficult conditions on other planets Thanks to the work of such scientists 12 people have walked on the Moon More than 500 people have spent a combined total of 29,000 days in space We have sent uncrewed missions to all the planets and some dwarf planets in our Solar System Voyager 1 which was launched in 1977 is preparing to leave our Solar System altogether We are a long way from being able to set up permanent colonies in space or on other planets or make space travel common but scientists are working on it During your lifetime you may be able to take a vacation on the Moon 5
