^^)why are the distances between objects in the

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1 Make Your Own Summary Summarize the key concepts of this chapter using a graphic organizer The Chapter Summary on the previous page will help you identify the key concepts. Refer to Study Toolkit 4 on pages to help you decide which graphic organizer to use. [11 ^'hy can you not see the new Moon? (I^Z^escribe how a total eclipse of the Sun would look from the Moon. Include a diagram with your description. (Ts^raw a diagram of the solar system, like the one shown below. Complete your diagram by labelling each object. Reviewing Key Terms 1. The Mesopotamians were the first for whom we have evidence of detailed astronomical observations. (7.1) ^^ yfearth on its axis and around the Smi. (7.1) (^C)jroups of stars that seem to form distinctive patterns are called. (7.2) (4!)Duringa ', the new Moon completely blocks the Sun. (7.3) ^^ )^ ' is a celestial object that orbits one or more stars, is spherical, and does not share its orbit with another object. (7.4) 6.) is the apparent motion of a planet opposite to the usual east-to-west motion. (7.4) that survives impact with the atmosphere and reaches the ground is called Knowledge and Understanding 1 ^ 8. Why was recording the movement of stars in the night sky important to early sky watchers? Cs^hy does the Moon have phases? ^O^dentify the phases of the Moon that are shown in the diagram below. The solar system ^^)why are the distances between objects in the solar system not measured in light-years? ^^^What name do astronomers give to the average distance between Earth and the Sun? ^J^6?^e planets are classified as the inner planets and the outer planets. What do you think this classification is based on? ^^^^escribe characteristics that all the outer planets share. (^^escribe the difference between Pluto and the eight planets. hat causes "shooting stars," the streaks of light that cross the night sky? ''20. Compare and contrast asteroids and meteoroids. 2 lydescribe a comet. Include a diagram and a definition in your description. Explain where comets originate and why comets have two tails. Thinking and Investigation r 22. The same side of the Moon is always visible from Earth because the Moon rotates at about the same rate as it revolves around Earth. W^ould a person living in a lunar colony experience day and night? Explain your answer. 312 MHR»Unit3 The Study of the Universe

2 23.yA solar eclipse always occurs about two weeks before or after a lunar eclipse. Explain why. Communication 24. Q I ^ S Different t)t3es of celestial objects in DI \ E the solar system and universe have distinct properties that can be investigated and quantified. Create a table with planetary facts. Include mass, diameter, period of rotation, moons, average surface temperature, atmosphere (yes/no), special features (such as rings), orbital radius, and any other characteristics that interest you. Prepare a brochure using the information in your table. Include drawings of the planets. A hypothetical space agency will use the brochure to select a planet to research, by sending a ^IG 26. spacecraft to it. People use observational evidence of the properties of the solar system and the universe to develop theories to explain their formation and evolution. Explain how studying objects in the Oort Cloud and Kuiper Belt can help astronomers understand the solar system. BIG! Space exploration has generated valuable knowledge but at enormous cost. Assess the NEOSSat program. Write an editorial for the school newspaper in which you express your opinion on Canada's financial and technological contributions. 7.i)raw a diagram to show the difference between rotation and revolution. 28.j!,xplain why constellations appear to move through the night sky. ^^^^^escribe why Earth experiences seasons. Include a drawing that shows why the surface of Earth warms in the summer and cools in the winter. Application 30. Sometimes a halo appears around the Moon. Some people say that the halo means bad. weather is approaching. Research the causes of the halo on the Internet or in other sources. (1^^ Suppose that astronomers spotted a large rock at approximately the same distance as the Moon is from Earth, on a colhsion course with Earth. How much time would there be to prepare? Would there be minutes, days, months? Follow these steps to estimate an answer: a. Earth takes about s to orbft the Sun. Consider Earths orbit to be circular, with a radius of km. Estimate Earths orbital speed. b. Suppose that Earth runs into an asteroid orbiting at the same speed as Earth, in the opposite direction. How fast would the object appear to be approaching Earth? c. How long would the object take to cover the km distance between Earth and the Moon? Chapter 7 The Night Sl<y MHR 313

3 Make Your Own Summary Summarize the tey concepts of this chapter using a graphic organizer The Chapter Summary on the previous page will help you identify the key concepts. Refer to Study Toolkit 4 on pages to help you decide which graphic organizer to use. Reviewing Key Terms (^^ight from a star is a form of.(8.1) 2. telescopes use mirrors to collect light, and use lenses to collect light. (8.1) (^X^Dnce a reaches a telescopes temperature of C, the process of (8.2) begins. /4.) are dark areas on the Suns ^surface. (8.2) Sun is located in the band of stars called the in a 10. To answer these questions, refer to Figure 8.15, which shows some Canadian contributions to the International Space Station. a. Give an example of a hazard that humans face when they are in space. b. What technology was developed in response to the hazard in part (a)? ^^T)Describe how the Sun is necessary for life as wc know it. ^J^2^opy the figure below into your notebook, and fill in the three missing percentages. Solar radiation reflected by clouds, the atmosphere, and Earth's surface, % Solar radiation absorbad by Earth's atmosphere, % diagram. (8.3) ^^After the Sun becomes a red giant, it will contract and eventually become a.(8.4) olar radiation absorbed by Earth's surface % This diagram shows what happens to solar radiation when it reaches Earth. (^^}^ massive star will end up as either a or a (^T3?^xplain why the Sun is about 30 percent larger today than about five bilhon years ago. depending on the star's initial mass. (8.4) Knowledge and Understanding 8. How have partnerships between the Canadian government and Canadian businesses contributed to the development of technology used in space research and exploration? ^!jbescribe how an event on the Sun can affect Earth. Use an example in your answer. ^^^^^olar flares are associated with what features on the Sun's photosphere? hat evidence is there that the Sun rotates? escribe how a star's spectrum is useful. )n a graphic organizer of your choice, list the evidence that supports the solar nebula theory. 18. Using the information in Table 8.2, compare and contrast MOST and the Hubble Space Telescope. Use a comparison strategy of your choice. 356 MHR Unit 3 The Study of the Universe

4 DO Create a Hertzsprung-Russell diagram like the one below in your notebook. Label the diagram with the following terms: main sequence, red giants, supergiants, and white dwarfs. Also, label the axes with the missing words. 25. Space exploration has generated U i %J S valuable knowledge but at enormous cost. In this chapter, you learned about some of the risks associated with space exploration as well as some of the knowledge gained. Express your opinion on the pros and cons of space exploration in an to a friend. 26. Review the issues in Table 8.3. Take a position on whether you think it is ethical to send people to Mars. State your position in writing, and support it with your reasons. (27;X'escribe the important stages of a star's life. 01 E hotter cooler Use any method of presentation you wish. Application 28. In what ways do satellites benefit your life bluer redder and the lives of your family and friends? A Hertzsprung-Russell diagram Thinking and Investigation ^9 20. To launch humans into space requires very specialized systems. List the essential systems that aerospace engineers must include in a spacecraft to support humans in space, but that would not normally be needed for unpiloted spacecraft. 21. Why are white dwarfs hot as well as dim? ^^^It is a common misconception that if a star turns into a black hole, the newly formed black hole will begin to gobble up everything around it. Explain why this assumption is false. 23. Why do you think the MOST satellite is called "Canada's Humble Space Telescope"? Communication 24?)n! 1^ S People use observational evidence of»j the properties of the solar system and the universe to develop theories to explain their formation and evolution. Describe, using an example from this chapter, how astronomers use observational evidence to develop a theory to expkiin the formation of the solar system. 29. The Canadarm is an essential component of both the space shuttle system and the International Space Station. Research the Canadarm by visiting the Canadian Space Agency's website. Identify one medical benefit that has resulted from the development of Canadarm technology. 30. Robots on other planets can be controlled from Earth, but it takes several minutes for the instruction to reach the robot because of the vast distances between planets. a. A camera on a Mars rover detects a hole directly in its path 100 m ahead (the length of a football field). Mars is located relative to Earth such that the signal takes 20 min to get to Earth. The technician on Earth sends a "stop" command. If the rover travels at 10 cm/s, will it stop before the hole? What is the maximum safe speed for the rover to operate to avoid missing the hole? (Hint: V = d/t, where v is speed, d is distance, and t is time.) b. Suggest a way in which the risk to rovers on distant planets might be minimized. Chapters Exploring Our Stellar Neighbourhood MHR 357

5 Make Your Own Summary Summarize the fcey concepts of this chapter using a graphic organizer The Chapter Summary on the previous page will help you identify the key concepts. Refer to Study Toolkit 4 on pages to help you decide which graphic organizer to use. (^9^hat led William Herschel to conclude that the Sun is part of a huge galaxy of stars? ^}Identify each celestial object below. Reviewing Key Terms Match each key term Hsted below to its definition. a. big bang e. dark matter b. cosmic microwave f. galaxy background g. Milky Way galaxy c. cosmology d. dark energy 1. A(n) is a huge collection of stars, planets, gas, and dust held together by gravity. (9.1) 2. The galaxy that includes our solar system is called the t.jato:s4l (9-1) 3. The study of how the universe began and evolved is called ^,..(9.2) 4. According to the theory, the universe began from an incredibly dense state. (9.2) 5. The universe has cooled to a chilly -270 C during its billions of years of expansion. The leftover radiation from the big bang is called the r radiation. (9.2) 6. Stars in the outer regions of galaxies are revolving around the centre faster than expected. This evidence suggests that much of the matter within each galaxy must be in the form of,.(9.3) 7. Recent observations have revealed the presence of a mysterious energy that is causing increased expansion of the universe. This energy is called.(9.3) /Ti J Which type of galaxy do astronomers consider to be the oldest? /12.]What surprising discovery was made by Edwin Hubble? (^l^xvhat conclusion can be drawn from the fact that the universe is observed to be expanding? 14. List two spinoff technologies from the exploration of space. (^T5)what prediction was made by George Gamow and subsequently verified by Robert Wilson and Arno Penzias? ^^y^rrange the following statements in order of time, from earliest to most recent. a. The Sun and solar system formed. b. The cosmic microwave background radiation cooled to -270 C. c. The Milky Way galaxy formed. d. The earliest stars formed. Knowledge and Understanding ^^Arrange the following objects in order of size, from smallest to largest: galaxy cluster, universe, star, galaxy, globular cluster. e. The big bang happened. (2> ITJf dark matter cannot interact with ordinary matter, how do scientists know that it exists? ^^^^ow is dark matter distributed in galaxies? 386 MHR Unit 3 The Study of the Universe

6 ^j}why do astronomers think that the universe must have started from something compact and dense? Thinking and Investigation Sfm (^^^e sphere of stars around a galaxy is made exclusively of old stars. What does that tell you about galaxy formation? 21. Use Figure 9.9 on page 371 to calculate the rate of the expansion of the universe. ^'22^Consider three identical galaxies. Galaxy A is coming toward us, galaxy B is going away from us, and galaxy C is not moving, relative to the Milky Way galaxy. How will their line spectra be different? 23. Make a concept map showing the life history of a massive star. Communication 24. a: Different types of celestial objects in the solar system and universe have distinct properties that can be investigated and quantified. Explain how the properties of globular clusters were investigated and how the resulting discoveries led to further understanding of the Milky Way galaxy. S Astronomers use observational evidence of the properties of the solar system and universe to develop theories that explain their formation and evolution. Explain how astronomers used observational evidence to support the big bang theory. 26. BIG C/5 Space exploration has generated a: 2 valuable knowledge, but at an enormous cost. Research rechargeable tools. Describe how and when rechargeable tools became a spinoff technology from NASA's space program. 27. NASA usually allows shuttle missions to take place if the chance of a catastrophic collision with space junk is not greater than one in 200. Do you think space missions with a greater chance of a catastrophic collision are wwth the risk to human life or the huge expense? Work with a partner to complete a chart outlining the costs and benefits of space exploration that carries a risk of collision with space junk. ^ ^^^^?)Drganize the evidence that supports the big bang theory in a graphic organizer. Application 29. Identify three careers related to astronomy and (^^^^hy space exploration in this chapter do celestial objects that are farther away sometimes look younger than if they were closer to us? 31. In the science fiction television series Star Trek, the writers felt that the crew of the starship Enterprise would grow bored if they had to wait decades between adventures. So, the writers invented "warp drive" to get the crew around the galaxy much faster. Warp 9.9 is about 3000 times faster than the speed of Hght. In reality, this is impossible. In science fiction, however, it is fun. Calculate how long it would take the crew of the Enterprise, at warp 9.9, to a. reach the nearest star, about 4 light-years away b. reach the centre of the Milky Way galaxy c. go to the far side of the galaxy d. go around the galaxy at the Sun's distance from the ccnlre of the galaxy Chapter 9 The Mysterious Universe MHR 387