Big Idea: People develop & use technology to explore & study space. Unit 4 Exploring Space Big Idea: People develop & use technology to explore & study space.

Have you ever thrown a rock into a lake Have you ever thrown a rock into a lake? What happens when you throw a small pebble into the water? The resulting ripples are small, and each wave is close to the next wave; they have a short wavelength. Now, consider what would happen if you threw a large boulder into the water. Instead of small ripples, you get large waves. These larger waves are spaced further apart from one another. Thus, they have a large wavelength. The heat produced by the Sun travels from the Sun to the Earth via waves known as electromagnetic waves. These waves can vary greatly in their wavelength.

Energy Around Us There are waves of energy and light moving around us in the form of TV and radio transmissions, gamma radiation from space, and heat in the atmosphere. Scientists call them all electromagnetic radiation. The waves of energy are called electromagnetic (EM) because they have both electric and magnetic characteristics. Physicists classify them by the frequency of their wavelength, going from high to low frequency. When a wave has a lot of energy, it could be a gamma ray or x-ray. If it has low frequency, it has less energy and could be a TV or radio wave. 

A continuous range of a single feature, in this case ,wavelength SPECTRUM A continuous range of a single feature, in this case ,wavelength

Because the electromagnetic waves traveling to the Earth from the Sun come in a variety of lengths, scientists consider them to be a spectrum. Thus, we refer collectively to all these waves as the electromagnetic spectrum. The electromagnetic spectrum is a big word that simply refers to all the different sized waves of energy traveling outward from the Sun, as well as from many other objects in the Universe. To better understand the electromagnetic spectrum, scientists break it into three separate categories or divisions. The shortest waves are called ultraviolet waves. The medium sized waves are called visible light waves, and the longest waves are called infrared waves. Even longer waves also are categorized into radio waves, microwaves, and so forth.

What are electromagnetic waves? Electricity can be static, like what holds a balloon to the wall or makes your hair stand on end.  Magnetism can also be static like a refrigerator magnet. But when they change or move together, they make waves - electromagnetic waves. Electromagnetic waves are formed when an electric field (shown as blue arrows) couples with a magnetic field (shown as red arrows). The magnetic and electric fields of an electromagnetic wave are perpendicular to each other and to the direction of the wave. James Clerk Maxwell and Heinrich Hertz are two scientists who studied how electromagnetic waves are formed and how fast they travel.

EM Waves can be generated by devices such as cell phones, microwave ovens, and flashlights. Electromagnetic Radiation is also generated by heat Very cool materials radiates or emits energy (radio waves) Warmer objects (infrared) Emit light- object must be hot (light bulb)

Different portions of the EM Spectrum interact with matter differently Radio waves pass easily through space and the atmosphere Infrared radiation allows to see at night (special equipment) Microwaves-penetrate a small distance into many materials, where they are absorbed)-cook food Ultraviolet-workbook page 190

Waves can be described by either their wavelength or frequency

HIGHER FREQUENCY WAVE = SHORTER WAVELENGTH

Waves http://www.ducksters.com/science/light_spectrum.php Wavelength-distance between one point on a wave & the nearest point just like it. Frequency-number of wavelengths that pass a fixed point each second. Frequency is expressed in hertz (Hz). Amplitude - the energy carried by a wave (tall or short waves) The electromagnetic spectrum includes a wide range of light waves, some that we can't see. Some of the non-visible types of waves are radio waves, microwaves, infrared rays, and X-rays. These types of waves have all sorts of uses in science and technology.

The electromagnetic spectrum includes a wide range of light waves, some that we can't see. Some of the non-visible types of waves are radio waves, microwaves, infrared rays, and X-rays. These types of waves have all sorts of uses in science and technology.

http://www.kidsgeo.com/geography-for-kids/0057-ultraviolet-waves.php Electromagnetic spectrum – all the different sized waves of energy traveling outward from the sun, as well as from many other objects in the universe. Radio waves- prime purpose of radio is to give information from one place to another without wires. (i.e. GPS, radio, television, rockets)- LONGEST WAVELENGTH and LOWEST FREQUENCY, Produce Sound waves (not electromagnetic) Energy traveling as electromagnetic waves is called electromagnetic radiation. Different types of electromagnetic waves interact with matter differently. Objects can give off heat, light, and other forms of electromagnetic energy. 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. 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. 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.

Microwaves A microwave is an electromagnetic wave with a very long wave length. Microwaves are also used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships and weather forecasters. Prolonged exposure to microwaves is known to cause "cataracts" in your eyes, which is a clouding of the lens, preventing you from seeing clearly (if at all!) So don't make a habit of pressing your face against the microwave oven door to see if your food's ready! Recent research indicates that microwaves from mobile phones can affect parts of your brain - after all, you're holding the transmitter right by your head. Other research is inconclusive, although there is a feeling that you're more vulnerable if you're young and your brain is still growing Cooking meals

Infrared -equipped telescopes to penetrate dusty regions of space, detect objects such as planets. Photographers use film that is sensitive to infrared rays to take pictures in places where there is no visible light. Burglar alarms also use infrared. Infrared waves are commonly referred to has heat rays. Heat is in fact infrared radiation. Hold your hand next to a hot stove. Do you feel the heat radiating off of the stove and traveling towards your hand? If our eyes could see infrared radiation, what would it look like? You would see anything that produces heat, including plants and animals, no matter how dark it was. On average, the Sun produces very little infrared radiation compared to the amount of ultraviolet radiation and visible light that it creates. Radio waves- Microwaves - A microwave is an electromagnetic wave with a very long wave length. geographers get a unique type of map. Microwaves are also used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships and weather forecasters. Prolonged exposure to microwaves is known to cause "cataracts" in your eyes, which is a clouding of the lens, preventing you from seeing clearly (if at all!) So don't make a habit of pressing your face against the microwave oven door to see if your food's ready! Recent research indicates that microwaves from mobile phones can affect parts of your brain - after all, you're holding the transmitter right by your head. Other research is inconclusive, although there is a feeling that you're more vulnerable if you're young and your brain is still growing Infrared waves-equipped telescopes to penetrate dusty regions of space, detect objects such as planets. Photographers use film that is sensitive to infrared rays to take pictures in places where there is no visible light. Burglar alarms also use infrared. Visible light-As you look around the room, everything you see has these waves bouncing off of them. If they didn’t, you would not be able to see them. What your eyes pick up and turn into a picture in your brain are these visible light waves. Ultraviolet Waves Waves measuring under 0.4 micrometers are referred to as ultraviolet. Long term exposure to ultraviolet radiation would seriously hurt and even kill most lifeforms on Earth, including humans. The Sun produces a significant amount of ultraviolet waves. Fortunately, most of these waves never reach the surface of the Earth. They are either absorbed, or reflected and bounced away by molecules in the upper atmosphere. X-rays-The images produced by X-rays are due to the different absorption rates of different tissues. Calcium in bones absorbs X-rays the most, so bones look white on a film recording of the X-ray image , called a radiograph. Fat and other soft tissues absorb less, and look gray. Air absorbs the least, so lungs look black on a radiograph

Visible light-small spectrum that we see divided up into colors of the rainbow. As you look around the room, everything you see has these waves bouncing off of them. If they didn’t, you would not be able to see them. What your eyes pick up and turn into a picture in your brain are these visible light waves. Shorter visible light wavelengths are bluer in color, while longer visible light wavelengths are redder in color. The wavelengths detectible by the human eye represent only about 3% of the total electromagnetic spectrum -Only images we can see without computer enhancement. Ultraviolet Waves Waves measuring under 0.4 micrometers are referred to as ultraviolet. Long term exposure to ultraviolet radiation would seriously hurt and even kill most lifeforms on Earth, including humans. The Sun produces a significant amount of ultraviolet waves. Fortunately, most of these waves never reach the surface of the Earth. They are either absorbed, or reflected and bounced away by molecules in the upper atmosphere. Extremely dangerous to living organisms X-rays-The images produced by X-rays are due to the different absorption rates of different tissues. Calcium in bones absorbs X-rays the most, so bones look white on a film recording of the X-ray image , called a radiograph. Fat and other soft tissues absorb less, and look gray. Air absorbs the least, so lungs look black on a radiograph - physicians use X-rays to examine the inside of the body. X rays come from fast moving electrons

Gamma rays- produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are made by nuclear explosions, lightning, and radioactive decay. The TOP TWO ROWS show the wavelengths that penetrate the earth's atmosphere. You can see that radiowaves and visible light easily penetrate the earth's atmosphere. Microwaves and Infrared radiation also penetrate the atmosphere, although to a lesser extent. You can also see that light (visible electromagnetic radiation) constitutes a very small part of the electromagnetic spectrum. The SECOND TWO ROWS show some common objects of different sizes within this range. A large office building can be 102 m (100 meters) high. A bacterium is about 10-6 m (0.000001 meters) in diameter. The nucleus of an atom is about 10-12 m (0.000000000001 meters) in diameter. You can see that frequency increases from left to right, whereas the wavelength decreases from left to right. In fact, since the speed of radiation is known (299,792,458 meters per second, or 186,282.397 miles per second), you can always determine the frequency if you know the wavelength. Just use this equation: Gamma rays have the smallest wavelengths and the most energy (fastest frequency) of any wave in the electromagnetic spectrum . What sort of objects can stop a gamma ray (obviously earth’s atmosphere). Lead and concrete can stop gamma rays. Other types of nuclear radiation are alpha and beta which you will learn more about next year. The saying, hold a cookie in your hand, put one in your pocket or just eat the cookie.

Beyond the Clouds Unit 4 Lesson 2 Technology for Space Exploration Rocket -a machine that uses gas, often from burning fuel, to escape Earth’s gravitational pull. Rockets are used to launch vehicles into space. In early missions, capsules containing the crews detached from the rockets, which burned up. Upon return, the capsules “splashed down” in the ocean and were recovered but not reused. A space shuttle is a reusable spacecraft that launches with the aid of rocket boosters and liquid fuel. It lands on Earth like an airplane. A space shuttle carries astronauts and supplies back and forth into orbit around Earth. Two white, solid rocket boosters (SRBs) help the shuttle reach orbit. These booster rockets detach and are reused. People live and work in space on space stations. A space station is a long-term crewed spacecraft on which scientific research can be carried out. Currently, the International Space Station (ISS) is the only space station in Earth orbit. Six-member crews live aboard it for an average of six months. Many scientific studies are conducted on the ISS, including the effects of weightlessness on the human body and observations of Earth systems. For space travel, challenges include having sufficient supplies of air, food, water, and fuel for the long journey. The spacecraft must be insulated from the intense cold of space and harmful radiation from the sun. Experiencing weightlessness, astronauts find it difficult to eat, drink, and sleep without floating, and their muscles and bones weaken. Telescopes have been placed in Earth orbit to circumvent the distortion of light by Earth’s atmosphere. The Hubble Space Telescope detects light from objects in space and sends images back to Earth. The Chandra X-Ray Observatory and Compton Gamma-Ray Observatory were placed in space because Earth’s atmosphere blocks most X-rays and gamma rays. A space probe is an uncrewed vehicle that carries scientific instruments to distant objects in space. Probes have been useful for studying the atmospheres of the gas giant planets. An atmospheric entry probe is dropped from a spacecraft into the planet’s atmosphere. During its descent, it relays data back to the spacecraft. An orbiter is an uncrewed spacecraft that is designed to enter into orbit around another object in space. Controllers on Earth can place a spacecraft into orbit around a distant planet or its moons. Cameras and other instruments on the orbiter can photograph the planet’s surface and measure temperatures and surface features. A lander is a craft designed to land on the surface of a body in space. Landers have been placed successfully on the moon, Venus, and Mars, and on Saturn’s moon Titan. The images taken by a lander are more detailed than those taken by an orbiter. No longer to space program-speed, design, cost efficient, carry satelites or other equipment for a cause http://exploration.grc.nasa.gov/education/rocket/rktstomp.html http://school.discoveryeducation.com/clipart/clip/rockets.html

Unit 4 Lesson 2 Technology for Space Exploration The Global Positioning System (GPS) - a network of 24 satellites that orbit Earth. These satellites continuously send microwave signals. A GPS receiver receives signals from at least four satellites at one time. Once a GPS receiver on Earth picks up the signals, the technology in the receiver can determine the location of the receiver on Earth’s surface. Use radio waves How can satellites help a lost hiker? The first man-made satellite was launched by the Soviet Union in 1957. It was called Sputnik 1 and it studied the atmosphere. Since then thousands of satellites have been launched into space for lots of different reasons: for communications (TV, radio, telephone and Internet - the signals are sent up to the satellites, they are ‘reflected’ off the satellites at a different angle like light off a mirror or a ball off a wall, and are received back down in another part of the world), weather forecast, studying the Earth itself, looking at plant cover and the effects of climate change, etc. Copyright © Houghton Mifflin Harcourt Publishing Company 19