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Chpt 18 Earth Scienc
| Question | Answer |
|---|---|
| How did ancient cultures mark the passage of time? | Built observatories to observe the movement of objects, such as, stars, planets, and moons to mark the passage of time |
| What is astronomy? | The study of the universe |
| What is a year? | Time required for the Earth to orbit once around the sun |
| What is a month? | Division of the year that is based on the orbit of the moon around the sun |
| What is a day? | Time required for Earth to rotate once on its axis |
| What did the earliest astronomers use to learn about the universe? | Astronomical observations and oral histories |
| What is the Ptolemaic Theory? | The Earth is at the center of the universe |
| What was Copernicus's Theory? | The sun is at the center of the universe |
| What tool did Brahe use to make detailed astronomical observations? | Mural quadrant |
| What did Brahe believe? | The sun and the moon evolved around the earth and that the other planets revolved around the sun |
| Based upon Brahe's work, what did Kepler announce? | All the planets revolve around the sun in elliptical orbits and that the sun is not in the exact center of the orbits |
| Who was one of the first people to use a telescope to observe objects in space? What did he discover? | Galileo Galilei; Craters and mountains on the Earth's moon, four Jupiter's moon, sunspots on the sun, and the phases of Venus |
| What did Isaac Newton show? | All objects in the universe attract each other through gravitational force |
| What did Edwin Hubble prove? What did his data confirm? | Other galaxies existed beyond the edge of the Milky Way; Beliefs of some astronomers that the universe is much larger than our galaxy |
| How are computers used today in astronomy? | Help process data and control the movement of telescopes |
| What is a telescope? | Instrument that collects electromagnetic radiation from the sky and concentrates it for a better observation |
| What are optical telescopes used for? | Study visible light from objects in the universe |
| What are the functions of the two lenses in an optical telescope? | Collects light and forms an image at the back of the telescope; Magnifies the image produced by the objective lens |
| What is a refracting telescope? | Telescope that uses a set of lens to gather and focus light from distant objects |
| In a refracting telescope, how do the two lens work together to create an image? | Objective lens that bends light that passes through it and focus the light to be magnified by an eyepiece |
| What is a reflecting telescope? | Telescope that uses a curved mirror to gather and focus light from distance objects |
| In a reflecting telescope, how is the image created? | Light enters the telescope and is reflected from a large, curved mirror to a flat mirror |
| Three advantages of using a reflecting telescope | 1. Mirrors can be very large 2. Curved mirrors are polished on their curved sides 3. Mirrors can focus all colors of light to the same focal point |
| How is an image created in the Keck Telescope in Hawaii? | Very large reflecting telescopes, several mirrors work together to collect light and focus it in the same area |
| How does the atmosphere affect the images produced by optical telescopes? | Earth's atmosphere causes starlight to shimmer and blur to the motion of the air above the telescope |
| Where do astronomers often build telescopes? Why? | Dry area to avoid moisture in the air; mountaintops because the air is thinner at higher elevations |
| Why is the Hubble Space Telescope in space? | Avoid interference by the atmosphere |
| What is the electromagnetic spectrum? | Frequencies or wavelengths of electromagnetic radiation |
| What are non optical telescopes used for? What do non optical telescopes detect? | Study invisible radiation; detect radiation that cannot be seen by the human eye |
| What are radio telescopes used for? Why are radio telescopes used? | Detect radio waves; radio wavelengths are about 1 million times longer than optical wavelengths and radio telescopes do not have to be as flawless as the lens and mirrors of optical telescopes |
| Why do astronomers link telescopes together? | Work like a signal giant telescope then |
| Why have scientists placed ultraviolet telescopes, infrared telescopes, gamma-ray telescopes, and X-ray telescopes in space? | Most electromagnetic waves are blocked by Earth's atmosphere |
| What is the purpose for the Chandra X-Ray Observatory? | Detect black holes and some of the most distant objects in the universe |
| What are constellations? | Sections of the sky that contain recognizable star patterns |
| Why was it important in early ancient culture to study understand the location and movement of constellations? | Helped people navigate and keep track of time |
| How many constellations are in the sky? | 88 |
| Why are different constellations visible in the Northern and Southern Hemispheres? | Different portions of the sky are visible from the Northern and Southern Hemisphere |
| What is an astrolabe used for? | Determining the altitude of a star by measuring the angle between the horizon and a star |
| What is altitude? | Angle between an object in the sky and the horizon |
| What is zenith? | Point in the sky directly above an observer on Earth |
| What is the horizon? | Line where the sky and the Earth appear to meet |
| Describe how astrolabe works. | Location of a star or planet relative to where you are by using three points of reference. Measures the angle between the horizon and a star to determine the altitude |
| What are circumpolar stars? | Stars that can be seen at all times the year and all times of night |
| Why are different stars seen in the night sky at different times of there year? | The Earth travels around the sun, different areas of the universe of the universe are visible |
| What is a light-year? | Distance that light travels in one year |
| How far does light travel in one year? | About 9.46 trillion kilometers in one year |
| What is the dropper effect? | Increase or decrease of sounds that moves toward or away from the source and observer |
| Describe how the redshift occurs. | If a light source is moving quickly away from an observer, the light given off looks redder than it normally does |
| Describe how the blueshift occurs. | Star or galaxy is moving toward an observer, its light appears bluer than it normally does |
| What evidence did Hubble use to prove the universe is expanding? | Light from galaxies and stars to study the general direction that objects in the universe are moving |
Created by:
romfo