Chapter 19 Exploring Space. I. Fill in the blank

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1 Chapter 19 Exploring Space 1. All radiation is classified by wavelength in the electromagnetic spectrum. 2. Two types of telescopes that collect visible light are refractors and reflectors. 3. An uncrewed spacecraft is a(n) space probe. 4. Reflecting telescopes use a(n) mirror to magnify images. 5. Refracting telescopes use a(n) lens to magnify images. 6. A satellite orbits another object. 7. Thrust is the force that propels a rocket forward. 8. Radio waves travel at the speed of light. 1. Why do optical telescopes only work at night, while radio telescopes work all day and all night long? The Sun is a source of visible light. Optical telescopes collect visible light, and so they can only be used when the Sun s light does not interfere (at night). The Sun is NOT a source of radio waves, so it will not interfere with radio signals at any time. 2. Give a reason for putting a telescope in space. Give a reason for putting a telescope on a mountain. Some electromagnetic radiation cannot penetrate Earth s atmosphere, such as x rays and gamma rays, so telescopes designed to collect those types of radiation must be above Earth s atmosphere. A telescope might be placed on the mountain to be above the clouds, or more likely to have less atmosphere above it. The atmosphere is what causes the twinkling effect of stars which distorts images taken by telescopes. 3. What is an advantage of a multistage rocket? A multistage rocket disposes of parts of the rocket when those parts run out of fuel. So in a way it is getting rid of dead weight so that the rocket becomes lighter and more fuel efficient. 4. What are three things that all space probes have in common? All space probes are unmanned. What they have in common are: 1. power system 2. communication system 3. scientific instruments

2 Chapter 20 The Sun Earth Moon System, Lesson 1 Earth s Motion 1. A solstice occurs when one of the poles is aimed toward the Sun. 2. An equinox occurs when the Earth s axis is parallel to its orbit. 3. When a hemisphere is aimed toward the Sun, the sunlight is at a high angle and is called direct light. 4. When a hemisphere is aimed away from the Sun, the sunlight is at a low angle (spread out) and is called indirect light. 5. The tilt of the Earth s axis is a key reason why we have the seasons. 6. If the Earth did not rotate, then we would not have day and night. 7. The seasons are a result of the changing angles of sunlight because of the Earth s tilt as it revolves around the Sun. 8. The gravitational pull of the Sun on Earth causes Earth to revolve around the Sun in a nearly circular orbit. 1. What causes the seasons? (Your answer needs to include tilt, revolution, angles of sunlight, and amount of solar energy received). The Earth revolves around the Sun on a tilted axis. This causes the angle of sunlight to change through the course of a year. The higher the angle, the more solar energy received. 2. Agree or disagree, and explain why. a. The Sun is directly overhead at the equator on each of the equinoxes. Agree, because each hemisphere must receive equal light. The equator is the dividing line between the two hemispheres b. On the summer solstice, the Sun can be viewed overhead in the northern hemisphere (the Tropic of Cancer to be precise). Agree, because the northern hemisphere is aimed toward the Sun, so the

3 light must be directly overhead in the northern hemisphere. Chapter 20 The Sun Earth Moon System, Lesson 2 Earth s Moon 1. The tilted orbit of the Moon is why we don t have an eclipse every month. 2. Dark, flat areas caused by ancient lava flows are called maria. 3. Light, mountainous areas are called highlands. 4. The Moon s surface is covered by craters, which vary in size. 5. The phase of the Moon is due to the relative positioning of Earth, Moon, and Sun. 6. The waning crescent occurs right before the new moon. 7. The waxing gibbous occurs right before the full moon. 8. Half of the Moon is always lit by the Sun. 9. The full moon occurs when the Moon s sunlit side completely faces Earth. 1. Draw AND label the moon phases in order. 2. Explain why we never see the far side of the Moon. The moon rotates once per one revolution around Earth. 3. The Moon has a wide range of temperatures. Come up with a cause and effect hypothesis to explain why. (hints: think about gravity and atmosphere). The Moon has a relatively small amount of mass compared to Earth. The smaller mass causes there to be a smaller amount of gravity. This means that the Moon cannot hold

4 onto an atmosphere. No atmosphere means that the Moon cannot trap heat. This leads to wide swings in temperature. Chapter 20 The Sun Earth Moon System, Lesson 3 Eclipses and Tides 1. The Moon is the main reasons for tides. 2. A solar eclipse occurs when there is a new moon. 3. A lunar eclipse occurs when the order is Sun, Earth, Moon. 4. A total lunar eclipse occurs when the Moon passes completely through Earth s umbra. 5. A partial lunar eclipse occurs when the Moon passes partly through Earth s umbra. 6. The penumbra is the lighter shadow surrounding the darker umbra. 7. A neap tide is when there is the least amount of difference between consecutive high and low tides. 8. A spring tide occurs during a full or new moon. 1. Why do most coastal regions experience two high tides and two low tides each day? The Earth rotates through the double tidal bulge in just over one day. 2. Agree or disagree, and explain why. a. A spring tide always occurs during a solar eclipse. Agree, because the Sun, Earth, and Moon must be aligned for a spring tide to occur and for a solar eclipse to occur. b. A spring tide is the same as a high tide. Disagree, because a spring tide contains a higher than normal high tide and a lower than normal low tide. 3. Explain (and draw) why lunar eclipses last longer than solar eclipses. In a solar eclipse, the Moon s umbra touches only a smaller portion of the Earth, which quickly rotates out of the umbra. In a lunar eclipse, the Earth s umbra is

5 much larger and it takes a while for the Moon to revolve through the umbra. See figure below. Chapter 21 The Solar System, Lessons Nuclear fusion is the source of the Sun s energy. 2. A comet is an icey object that comes from the Kuiper belt and orbits the Sun. 3. The inner planets are small, dense, rocky, and have no or few moons. 4. The outer planets are large, made of gas, not very dense, have rings, and have many moons. 5. The dwarf planets are located mostly in the Kuiper belt, except for one that is in the asteroid belt. They share or intersect other orbits. 6. bknknk This was supposed to be a question about solar wind. Just know that solar wind is a stream of charged particles coming from the Sun, and that the solar wind blows a comet s tail away from the Sun. 7. The asteroid belt is home to rocky objects between the orbits of Mars and Jupiter, while the Kuiper belt is home to icey objects beyond the orbit of Neptune. 8. A meteor is an object that is burning up in the atmosphere and is sometimes called a shooting star. 1. Answer the following questions about comets and meteors. a. Which direction does a comet s tail point, and why? A comet s tail always points away from the Sun because of the solar wind.

6 b. Where is each object located? A comet is an object that comes from the Kuiper belt (or farther away Oort cloud that we didn t talk about) and is in orbit around the Sun. A meteor is an object that is burning up in the atmosphere. c. Which is hot and which is cold. Explain how you know. A meteor is hot because it is an object that is burning up in the atmosphere. A comet is cold because it is an icey object from the Kuiper belt. 2. Compare at least two other planets to Earth in terms of size and atmosphere. A question like this would have a data table for you to interpret. Communication Systems (Not in your book) 1. A transmitter sends a signal. 2. A receiver receives a signal. 3. A decoder converts a signal to an understandable format. 4. An encoder converts an understandable format to a signal 1. Which of the four parts of a communication system would be LEAST likely to be on a space probe? Explain why. A decoder would be least likely. By definition, a space probe is unmanned. This would mean that the probe would not have to decode the signal for anyone because no one would be onboard.