Lesson 4 Exploring Space The Hubble Space Telescope is in orbit approximately 570 kilometers (355 miles) above Earth s surface. Why would scientists want a telescope in space? What advantages does the Hubble Space Telescope have over a telescope on Earth of similar size? 450 ENGAGE ESS.47 Identify and explain advances in technology that have enabled the exploration of space (ESS-M-C8) SI.29 Explain how technology can expand the senses and contribute to the increase and/or modification of scientific knowledge (SI-M-B3)
How do we learn about the planets? Materials Form a Hypothesis Do the tools that scientists use to study stars and planets affect the information they obtain? Write your answer as a hypothesis in the form If I change the tools I use to look at an object, then... Test Your Hypothesis Make a Model Cover a shoe box with newspaper, and tape the newspaper in place. The box represents a mystery planet. Place the box on the other side of the room. Observe View the box through a sheet of tinted, transparent plastic. Draw what you see, and include as many details as you can. shoe box newspaper clear tape sheet of thin, tinted, transparent plastic Observe View the box without the sheet of plastic. Draw what you see. Describe the differences from your first observation. Step Observe Walk near the box to view it at close range. Record what you observe. Draw Conclusions Infer How did your observation through the tinted, transparent plastic differ from your observations without the plastic? What new information did you obtain from a close-up observation? Explain your observations. Step Step Infer What is the difference between viewing a planet with a telescope on Earth and viewing it with a telescope in space? What causes the difference? What new information did you obtain from your flyby mission? Explore More What information might be obtained if a space probe landed on the mystery planet? How might you represent a landing with your model? Form a hypothesis, and design an experiment to test it. SI.14 Develop models to illustrate or explain conclusions reached through investigation (SI-M-A5) SI.22 Use evidence and observations to explain and communicate the results of investigations (SI-M-A7) 451 Also covers SI.15, SI.39 EXPLORE
Essential Question How do we explore space? ESS.47, SI.29 Vocabulary telescope, p. 452 space shuttle, p. 454 space station, p. 456 International Space Station, p. 457 Reading Skill Fact and Opinion Fact Opinion Technology e-glossary and e-review online at www.macmillanmh.com How do we observe objects in space? Until January 7, 1610, people observed the night sky using only their eyes. On that date, an Italian astronomer named Galileo Galilei looked at the sky through a telescope for the first time. A telescope is an instrument that makes distant objects seem larger and nearer. Optical Telescopes Galileo used an optical telescope, which uses lenses or mirrors to see objects by gathering visible light. Among the objects Galileo saw were four moons revolving around the planet Jupiter. At that time, astronomers were unaware that other planets had moons. Looking through an optical telescope makes a dim object, such as a star, seem brighter. It can also make objects appear larger so more details can be seen. When the diameter of the light-gathering lens or mirror is increased, more light is gathered and the planets appear larger. Today s optical telescopes have lenses and mirrors many times larger than those used in Galileo s telescope. Modern optical telescopes can magnify images of more distant planets and look farther into space. However, observers on Earth don t always get a clear view. This is because they look into space through Earth s atmosphere. As you learned, Earth s atmosphere is made of gases. As light from distant stars travels through the atmosphere, the change in density of these gases makes the light of stars appear fuzzy. This large globular cluster was seen through an optical telescope. 452 EXPLAIN
Telescopes in Space In 1990, the Hubble Space Telescope was placed into orbit around Earth. Objects that are billions of trillions of kilometers from Earth can be seen through the Hubble Space Telescope. In 2008, the Hubble took the first images of planets orbiting a star beyond our solar system. Placing telescopes in space allows scientists to see into space while avoiding Earth s atmosphere. The Hubble Space Telescope and other space telescopes gather more than visible light from objects in space. For example, they can detect the heat that is given off by a star. This supernova was seen by the Hubble Space Telescope. Radio Telescopes Back on Earth, radio telescopes record data from radio waves given off by objects in space. Groups of dishes focus the radio waves so the radio data can be recorded. Computers turn the data into an image. Radio waves can pass through Earth s atmosphere without interference. Quick Check Fact and Opinion Radio telescopes are better than space telescopes. Is this statement fact or opinion? Critical Thinking How would Galileo s observation of Jupiter s moons affect the idea that everything revolved around Earth? This image of an irregular galaxy was made by a radio telescope. 453 EXPLAIN
What is the space shuttle? Picture a disposable car: you spend thousands of dollars to buy it, you drive it once, and it disintegrates. With the early space program, that was essentially what NASA was doing. Rockets were used to launch a small capsule holding astronauts into orbit. Shortly after launch, sections of the rocket would begin to separate from the rest and reenter the atmosphere, burning up in the process. NASA began looking for ways to save money and resources. They thought that it would be less expensive and less wasteful to develop something that could be used over and over again. In the 1970s, NASA engineers developed the space shuttle, a reusable spacecraft to transport astronauts, satellites, and other materials to and from space. At launch, the space shuttle stands on end and is connected to an external liquid-fuel tank and two solid-fuel booster rockets. By the time the shuttle has reached an altitude of 45 km (28 mi ), the solid-fuel booster rockets have used all their fuel. They drop off and parachute back to Earth, where they can be recovered and used again. The external liquidfuel tank also separates and falls back to Earth, but it is not recovered or reused. launch of the space shuttle Discovery 454 EXPLAIN
The space shuttle was the first spacecraft to be able to carry large satellites to and from orbit. Once the booster rockets and liquid-fuel tank have separated from the shuttle and the shuttle reaches space, it begins to orbit Earth. While in orbit, astronauts aboard the shuttle can perform many different tasks. The cargo bay can be used to deploy artificial satellites. The shuttle can also be used to retrieve satellites already in space. The satellites can then be returned to Earth or, if they are not functioning properly, repaired onboard and returned to space. Astronauts can also use the cargo bay to conduct scientific experiments. After a mission the space shuttle glides back to Earth and lands in the same way an airplane does. As the shuttle comes toward land, it is traveling at approximately 340 km/h (210 mph)! A parachute is deployed to help slow it down on the landing strip. Each space shuttle orbiter is designed to be able to make about 100 trips into space. The space shuttle program is ending in 2010, and NASA scientists are working on spacecraft for Constellation, the next piloted spaceflight program. Quick Check Fact and Opinion NASA needed to develop the space shuttle because the space program was too expensive and too wasteful. Is this statement a fact or an opinion? Critical Thinking Why do the solidfuel rocket boosters need to be detachable? 455 EXPLAIN
What is a space station? The space shuttle was not designed for long missions. Its living area is small and does not offer the crew much room to live, exercise, and work. A space station is an object in space that allows astronauts to stay and work for extended periods of time. It has living quarters, work and exercise areas, and all the other equipment and support systems needed for humans to live and work in space. In 1973 the United States launched the space station Skylab. Crews of astronauts could spend nearly three months there performing experiments and collecting data on the effects on humans of living in space. In the late 1970s, NASA abandoned Skylab. In 1979 it fell out of orbit, most of it burning up in Earth s atmosphere. In 1986 the former Soviet Union began construction on the space station Mir, a word meaning peace. Over the next 15 years, Soviet (and later Russian) crews spent more time in space aboard Mir than crews from any other country. Cosmonaut Dr. Valeri Polyakov went to Mir in January 1994 and returned to Earth after 438 days in space. Part of his mission was to study the long-term effects of weightlessness, or what scientists refer to as microgravity. In 1995 the United States and Russia began cooperating on joint missions aboard Mir. Early that year, Dr. Norman Thagard was launched into orbit aboard the Russian Soyuz spacecraft, along with two Russian cosmonaut crewmates. Dr. Thagard was the first U.S. astronaut launched into space by a Russian booster and the first American resident of the Russian space station Mir. Throughout the course of the Shuttle-Mir Program, the space shuttle docked with Mir 11 times. Assembly of the ISS started in 1998 and continues today. 456 EXPLAIN
Docking the Space Shuttle Read a Photo Why would it be important for the space shuttle to be able to dock with a space station? Clue: Why was the space shuttle built? A Multinational Effort The relationship between Russia and the United States laid the groundwork for the International Space Station. A joint venture of more than 15 countries, the International Space Station (ISS) is an orbiting laboratory designed for long-term research projects. Construction on the space station began in 1998 with the launch of the Russian-built Zarya Module, also known as the Functional Cargo Block. Over the next three years, construction continued with rotating two- and three-person crews. In 2001 the U.S. laboratory Destiny was added to the space station. It included living quarters for science teams. Destiny allows scientists to conduct research on physical processes in microgravity. It also has a special window that allows high-quality photography of Earth. Geologists and other scientists interested in Earth s natural events can study pictures of avalanches, floods, glaciers, and wildfires from a different perspective. The ISS is scheduled to be complete in 2010 and will be in operation until 2016. A seven-person crew will be able to work comfortably aboard the station once it is finished. The International Space Station could one day be a construction site for spacecraft that will travel to the Moon and Mars. Quick Check Fact and Opinion List one fact and one opinion about the International Space Station. Critical Thinking How could the International Space Station aid in the exploration of the Moon or Mars? 457 EXPLAIN
How do we explore Mars? In the middle to late 1990s, NASA began to focus on the exploration of Mars, our closest neighbor. In 1996 two missions brought us more information about the planet than we previously had. The Mars Global Surveyor orbited Mars, taking high-quality photos of the planet s surface. The Mars Pathfinder, on the other hand, landed on the Martian surface. Large balloons, similar to giant automobile airbags, surrounded Pathfinder s landing module, absorbing the shock of impact. Pathfinder carried technology to study the surface of the planet, including a remote-controlled robot rover. The images taken by Surveyor suggested to scientists that water might have recently seeped to the surface of Mars in some areas. This type of information is especially important because water is believed to be a requirement for life as we know it to exist. Searching for Life on Mars Another orbiting spacecraft, the Mars Odyssey, began mapping the surface of Mars in 2002. Its data confirmed the findings of Surveyor that Martian soil contains frozen water in the southern polar area. To explore this further, NASA sent more robots to explore the surface of Mars. Twin rovers named Spirit and Opportunity were launched in 2003 and arrived at their separate destinations on Mars in 2004. They analyzed Martian rocks and soils, which told scientists more about Martian geology and provided clues about the role of water on Mars. Landforms on the surface of Mars may provide clues as to whether water could have existed there. Although they were designed to explore Mars for only 90 days, the two rovers were still active in 2010. NASA continued its exploration of Mars with the 2007 launch of a probe called Phoenix. In November 2008, Phoenix collected and analyzed soil samples from the north polar region of Mars. Phoenix verified the presence of water in the subsoil. What s Next? NASA has created the New Millennium Program (NMP). This project is designed to develop advanced technology that will let NASA send smart spacecraft into the solar system, controlled by onboard computer systems. This advancement will reduce the need for a large ground control crew and help to keep deployment costs down. 458 EXPLAIN
NASA scientists were also interested in finding out if water could exist at the Moon s poles. The 1998 Lunar Prospector mission was launched with that specific question in mind. The initial data from the mission indicated that frozen water might exist in the craters or beneath the surface. In 2009, NASA crashed a 2,000-kg (4,400-lb) rocket booster into the Moon s surface. Then a spacecraft flew through the resulting plume to collect data. The data indicated the presence of water. Future missions will involve more trips to the Moon to investigate its properties. Packing for Mars SI.3, SI.33 What would you need to bring with you if you went on an expedition to Mars? Infer Working in small groups, make a list of requirements you would need for survival on a Mars expedition. Explain each of the requirements and how you might meet them. Quick Check Fact and Opinion Finding liquid water may be the key to finding life on Mars. Is this statement a fact or an opinion? Critical Thinking Why do scientists want to find water on Mars or on the Moon? The Spirit rover on a Martian hill. Make a Model Design a Mars base station, and draw a picture of the outpost. Describe how each of the features of your station benefits the human inhabitants and meets their needs. Research some of the plans NASA has for future space stations or long-duration space missions. Compare and Contrast Compare your Mars base station to the International Space Station and to future NASA space stations. How are they similar? Are there features of a space station that you failed to take into account? Make a list of important features that were not in your original design. Improve your design based on your findings. 459 EXPLAIN
Getting to the Moon 1965 Project Gemini is started to develop a system for docking spacecraft. 1967 NASA chooses possible landing sites with unpiloted spacecraft in its Surveyor Program. 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1962 Project Mercury succeeds in sending a human into space. 1969 Astronauts land on the Moon for the first time. How did we get to the Moon? With all of the space probes and satellites we now have exploring our solar system, visiting the Moon may not seem like a big deal. However, in the early 1960s, space exploration was still very new, and sending a person to the Moon had never been done. In 1961 President John F. Kennedy challenged scientists to do just that. However, they needed to take careful steps to make sure the mission would be successful. Project Mercury was the first step. It involved sending an astronaut in a spacecraft into orbit around Earth and returning them both safely to see how well a human could function in space. In 1962 astronaut John Glenn flew the United States first piloted orbit of Earth. The next step, Project Gemini, involved two teams of astronauts meeting up with each other in orbit to try docking the two spacecraft together. 460 EXPLAIN Read a Diagram What steps were taken to allow astronauts to get to the Moon? Clue: Read the descriptions next to the photographs. Scientists also wanted to perfect ways of reentering Earth s atmosphere. The last step in reaching the Moon was Project Apollo. In 1969 astronaut Neil Armstrong became the first person to step onto the Moon. His words, That s one small step for man, one giant leap for mankind, were transmitted back to Earth and heard on radios and televisions by astonished audiences everywhere. Quick Check Fact and Opinion Give a fact and an opinion about the Moon landings. Critical Thinking Why did scientists send a person to the Moon instead of to another planet?
Visual Summary Make a Study Guide Make a three-door book. Inside each tab, complete the statement and provide details. Telescopes allow us to see objects in space. A space shuttle is a reusable spacecraft that transports people and things to and from space. Exploring Mars for signs of water and life is done with rovers taking photos and soil samples. Think, Talk, and Write Vocabulary The is a joint venture of more than 15 countries. Fact and Opinion Pathfinder did a better job of gathering data about Mars than Global Surveyor. Is this statement a fact or an opinion? Explain. Fact Opinion Critical Thinking Why might scientists want to find the existence of life on another planet? Test Prep Which was the first planet to be explored by a space probe? A Mercury B Venus C Jupiter D Mars Test Prep Which telescope did Galileo use to explore space? A Hubble Space Telescope B radio telescope C optical telescope D space telescope Essential Question How do we explore space? Art Link Space Station Poster Create a poster depicting a space station of the future. What would the people aboard need to survive? Label your drawing. Writing Link Explain a Telescope Choose one type of telescope and research it. Write a report explaining how the telescope works and what astronomical objects or events it is used to study. -Review Summaries and quizzes online at www.macmillanmh.com 461 EVALUATE
462 EXTEND In 1977 NASA launched the Voyager Interstellar Mission to explore Jupiter, Saturn, Uranus, Neptune, and their moons. Each of the mission s trips had to be very precisely planned. Speeds and distances had to be accurately calculated. The two Voyager spacecraft had to be close enough to each planet to collect data and to get a boost from that planet s gravity in order to be propelled toward their next destination. At the same time, the spacecraft had to be far enough away from the planets that they would not go into orbit around them. All of NASA s careful planning worked. The Voyager mission has provided scientists with new and closer looks at our farthest neighbors.
History of Science Jupiter 1979 Images show Jupiter s rings. Volcanic activity is observed on Io, one of Jupiter s moons. Europa, another moon, may have an ocean under its icy crust. Saturn 1980 Scientists get a close look at Saturn s rings. The rings contain structures that look like spokes or braids. Uranus 1986 Scientists discover additional dark rings around Uranus. They also see ten new moons. Voyager sends back detailed images and data on the planet, its moons, and its dark rings. Neptune 1989 Large storms are seen on the planet. One of these storms is Neptune s Great Dark Spot. Scientists thought Neptune was too cold to support this kind of weather. After observing these planets, the Voyager spacecraft kept traveling. They are the first human-made objects to go beyond the heliosphere. The heliosphere is the region of space reached by the energy of our Sun. It extends far beyond the most distant planets in the solar system. Connect to at www.macmillanmh.com Write About It Cause and Effect 1. What caused the Voyager spacecraft to be propelled from one planet toward the next? 2. How did scientists benefit from the Voyager missions? Cause and Effect Look for the reason why something happens to find a cause. An effect is what happens as a result of a cause. -Journal Research and write about it online at www.macmillanmh.com ELA.17 Analyze grade-appropriate print and nonprint texts using various reasoning skills, including: identifying cause-effect relationships (ELA-7-M4) 463 EXTEND
UNIT 8 Review Make a Study Guide Visual Summary Lesson 1 The Sun is a star made of mostly hydrogen and helium. It is the largest object in our solar system. Lesson 2 Gravity and inertia keep Earth in an elliptical orbit around the Sun. Lesson 3 Our solar system is made of the Sun, eight planets and their moons, dwarf planets, comets, asteroids, and meteoroids. Lesson 4 Gradual advances in technology have enabled the exploration and understanding of space. Assemble your lesson study guides as shown. Use this unit study guide to review what you have learned. DOK 1 Fill each blank with the best term from the list. asteroid, p. 443 meteor, p. 443 moon, p. 444 orbit, p. 425 planet, p. 436 revolution, p. 428 rotation, p. 426 space shuttle, p. 454 space station, p. 456 star, p. 413 1. Gravity and inertia keep Earth moving around the Sun in its. ESS.44 2. An object that enters Earth s atmosphere is called a(n). ESS.42 3. A large object that orbits a star is called a(n). ESS.43 4. The Sun is a in our solar system. ESS.39 5. Every 24 hours, Earth makes a complete, or spin on its axis. ESS.44 6. A rock that revolves around the Sun is called a(n). ESS.42 7. An object in space that allows astronauts to stay and work in space for a longer period of time is called a(n). ESS.47 8. A reusable spacecraft used to transport astronauts and satellites to space is called a(n). SE.47 9. Earth completes one in 365 days. SE.44 10. A natural object that orbits a planet is called a(n). ESS.42 464 -Glossary Words and definitions online at www.macmillanmh.com
DOK 2 3 Answer each of the following. 11. What materials make up a comet? A rock, water, and ice B rock, water, and dust C gas, dust, and ice D gas, meteroids, and dust ESS.42 18. Draw Conclusions What will happen if the Sun uses up all its hydrogen? ESS.39 19. Explanatory Writing Which two planets are shown below? Explain how you know which planets they are. ESS.43 12. The diagram above shows a representation of our solar system. Which number indicates the planet Earth? A 1 B 2 C 3 D 4 ESS.45 13. True or False If you travel toward Polaris, you will be moving south. Is this statement true or false? Explain. ESS.40 14. True or False The Sun rises in the east and sets in the west. Is this statement true or false? Explain. ESS.41 15. Critical Thinking What is the benefit of a technology such as the space station? What might be an unintended consequence? ESS.47 16. Fact and Opinion Use facts to explain what causes the seasons. ESS.44 17. Make a Model Design a model to explain Earth s rotation. Compare your model to your classmates models. What could you do to improve your design? ESS.44 20. What is in outer space? ESS.39, ESS.42, ESS.43, ESS.47 DOK 3 Different Looks? Your objective is to compare and contrast objects in the night sky. What to Do 1. Obtain an astronomy magazine, newspaper, or material from approved Internet sites that shows the current positions of planets in the night sky. 2. Use your unaided eyes, binoculars, or a small telescope to observe planets and stars. 3. Identify other objects in space that you may not be able to see. Analyze Your Results 1. Describe the colors of the planets, stars, and other objects. 2. Describe the shape of the planets stars, and other objects. 3. Make a poster to show the objects you described. ESS.42, ESS.43 -Review Summaries and quizzes online at www.macmillanmh.com 465
1 Study this diagram of our solar system. How can you describe Earth s location in our solar system? A. Earth is the center of our solar system. B. Earth is the third planet from the Sun. C. Earth is an outer planet. D. Earth is farthest from the Sun. ESS.45 2 Which statement about the Sun is correct? A. The Sun revolves around Earth. B. The Sun does not produce energy. C. The Sun is made mostly of nitrogen and helium. D. The Sun is the largest object in our solar system. ESS.39 3 Why is the North Star, Polaris, important? A. It is a beautiful star. 466 B. It can help you find your way if you are lost. C. If you follow Polaris, it will take you in a south direction. D. It will help you identify the constellation Orion. ESS.40 4 Cassandra noticed that the Sun was to her east in the morning and to her west in the evening. Why did the Sun seem to change position? A. Earth rotates on its axis. B. The Sun moves with Earth. C. The Sun moves around Earth. D. The Sun was behind a cloud. ESS.41 5 The table below shows information about four planets. Planet Period of Rotation Period of Revolution Mercury 58 days, 19 hours 88 days Venus 243 days, 16 hours 224 days, 17 hours Earth 23 hours, 56 minutes 365 days, 6 hours Neptune 19 hours, 6 minutes 60,190 days Based on information in the table, which conclusion could you make? A. Planets get larger the farther they are from the Sun. B. Neptune s revolution is the longest of the listed planets. C. Mercury has the shortest rotation. D. Planets get colder the farther they are from the Sun. ESS.43 6 What causes Earth s seasons to change? A. the Moon s revolution B. solar flares C. Earth s rotation around the Sun and the Moon s revolution around Earth D. Earth s tilted axis and revolution around the Sun ESS.44
7 What is the most significant discovery Galileo made using his telescope? A. The Sun revolves around Earth. B. The Sun revolves around Mars. C. Jupiter has moons. D. The Moon is a planet. ESS.47 8 Look at the diagram below. Sun What planet is shown in the illustration above? A. Earth B. Mars C. Jupiter D. Uranus ESS.44 axis of rotation 9 Which characteristic do the outer planets have in common? A. They have no moons. B. They are hot and rocky. C. They are large and very hot. D. They are large and made of gas. ESS.43 10 Which of the following is equivalent to one year? A. Earth s rotation B. The Sun s revolution C. Earth s revolution D. The Moon s revolution ESS.44 11 If Opportunity located evidence that water exists on Mars, what might scientists infer? A. Life could exist there. B. Mars has moved closer to the Sun. C. Air must also exist there. D. The Moon also has water. ESS.47 12 Which object s name changes based on its location? A. planet B. moons C. meteoroid D. the Sun ESS.42 13 Which of these planets have surfaces made of gases? A. Mercury, Jupiter, Saturn, Mars B. Earth, Jupiter, Mars, Venus C. Jupiter, Neptune, Uranus, Saturn D. Neptune, Uranus, Venus, Mercury ESS.43 Question Review Question Review 1 pp. 436 439 8 pp. 440 441 2 pp. 413 415 9 pp. 440 441 3 p. 416 10 pp. 426 429 4 pp. 426 430 11 pp. 458 459 5 pp. 438 441 12 pp. 442 443 6 pp. 428 429 13 pp. 438 441 7 p. 452 467