Unit 4 Lesson 1 Images from Space Copyright © Houghton Mifflin Harcourt Publishing Company

On the Same Wavelength? What is electromagnetic radiation? Unit 4 Lesson 1 Images from Space On the Same Wavelength? What is electromagnetic radiation? Energy traveling as electromagnetic waves is called electromagnetic radiation. Wavelength is the distance between two adjacent crests or troughs of a wave. Frequency is the number of waves per second. Copyright © Houghton Mifflin Harcourt Publishing Company 2

How is electromagnetic radiation classified? Unit 4 Lesson 1 Images from Space How is electromagnetic radiation classified? All wavelengths or frequencies make up the electromagnetic spectrum. A spectrum is a continuous range of a single feature—in this case, wavelength. Copyright © Houghton Mifflin Harcourt Publishing Company 3

How is electromagnetic radiation classified? Unit 4 Lesson 1 Images from Space How is electromagnetic radiation classified? Radio waves are the longest-wavelength, lowest-frequency electromagnetic waves. Microwaves have shorter wavelengths and higher frequencies than radio waves have. Infrared waves have shorter wavelengths and higher frequencies than microwaves have. They are sometimes called “heat radiation.” Copyright © Houghton Mifflin Harcourt Publishing Company 4

How is electromagnetic radiation classified? Unit 4 Lesson 1 Images from Space How is electromagnetic radiation classified? Visible light has a shorter wavelength than infrared has. Visible light allows you to see. Ultraviolet radiation, X-rays, and gamma rays have increasingly shorter wavelengths. Copyright © Houghton Mifflin Harcourt Publishing Company 5

The Better to See You With Unit 4 Lesson 1 Images from Space The Better to See You With What are some characteristics of electromagnetic radiation? Different types of electromagnetic waves interact with matter differently. Objects can give off heat, light, and other forms of electromagnetic energy. For example, physicians use X-rays to examine the inside of the body. Copyright © Houghton Mifflin Harcourt Publishing Company 6

What are some characteristics of electromagnetic radiation? Unit 4 Lesson 1 Images from Space What are some characteristics of electromagnetic radiation? In small amounts, electromagnetic radiation can be very useful. Large amounts of any type of radiation can cause problems because of the total amount of energy carried. Copyright © Houghton Mifflin Harcourt Publishing Company 7

What are some characteristics of electromagnetic radiation? Unit 4 Lesson 1 Images from Space What are some characteristics of electromagnetic radiation? Describe the differences between the various forms of electromagnetic radiation. Copyright © Houghton Mifflin Harcourt Publishing Company 8

What electromagnetic radiation reaches Earth? Unit 4 Lesson 1 Images from Space What electromagnetic radiation reaches Earth? In the atmosphere, atoms and molecules reflect or absorb some of the incoming radiation. Most visible light and radio radiation reach Earth’s surface. Some ultraviolet radiation reaches Earth. X-rays and gamma rays never reach Earth’s surface. Copyright © Houghton Mifflin Harcourt Publishing Company 9

What electromagnetic radiation reaches Earth? Unit 4 Lesson 1 Images from Space What electromagnetic radiation reaches Earth? What types of electromagnetic radiation reach Earth’s surface? Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unit 4 Lesson 1 Images from Space To See or Not to See How do people detect electromagnetic radiation from objects in space? Images of objects in space tell us about their positions and properties. Telescopes can collect all forms of electromagnetic radiation from space. Special detectors in telescopes must be used to form images from radiation other than visible light. Copyright © Houghton Mifflin Harcourt Publishing Company 11

How do people detect electromagnetic radiation from objects in space? Unit 4 Lesson 1 Images from Space How do people detect electromagnetic radiation from objects in space? Optical telescopes collect visible light with a mirror or a lens. A telescope that uses a mirror to collect light is called a reflecting telescope. A telescope that uses a lens to collect light is called a refracting telescope. Copyright © Houghton Mifflin Harcourt Publishing Company 12

How do people detect electromagnetic radiation from objects in space? Unit 4 Lesson 1 Images from Space How do people detect electromagnetic radiation from objects in space? What are the similarities and differences between a reflecting telescope and a refracting telescope? Copyright © Houghton Mifflin Harcourt Publishing Company 13

How do people detect electromagnetic radiation from objects in space? Unit 4 Lesson 1 Images from Space How do people detect electromagnetic radiation from objects in space? Nonoptical telescopes process and detect electromagnetic radiation other than visible light. Radio telescopes can detect radio waves from space and are often large. Images can be produced using special detectors and computer software. Copyright © Houghton Mifflin Harcourt Publishing Company 14

The View from Above How can people observe Earth from space? Unit 4 Lesson 1 Images from Space The View from Above How can people observe Earth from space? Remote sensing is the observation of Earth from space. Low-altitude satellites that observe Earth are in low Earth orbit. Geosynchronous satellites orbit Earth every 24 hours and always remain above the same location. Copyright © Houghton Mifflin Harcourt Publishing Company 15

What can you learn about Earth from satellite images? Unit 4 Lesson 1 Images from Space What can you learn about Earth from satellite images? Remote-sensing images can show human activities, how things change over time, and lights from populated areas. Remote-sensing images can also show population changes, forests, forest fires, weather patterns, and storms. Copyright © Houghton Mifflin Harcourt Publishing Company 16

Seeing Is Believing What can you learn from space images? Unit 4 Lesson 1 Images from Space Seeing Is Believing What can you learn from space images? Different types of radiation can reveal more features of an object than visible light alone reveals. Other forms of radiation can see through dust in space. Some images from space are the result of multiple images put together from multiple wavelengths of light. Copyright © Houghton Mifflin Harcourt Publishing Company 17