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Ch. 28 – The Sun-Earth-Moon System The cosmos radiation as electromagnetic waves are studied by scientists. Radio-Microwaves-Infrared- Visible-Ultraviolet-X-rays-Gamma.

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Presentation on theme: "Ch. 28 – The Sun-Earth-Moon System The cosmos radiation as electromagnetic waves are studied by scientists. Radio-Microwaves-Infrared- Visible-Ultraviolet-X-rays-Gamma."— Presentation transcript:

1 Ch. 28 – The Sun-Earth-Moon System The cosmos radiation as electromagnetic waves are studied by scientists. Radio-Microwaves-Infrared- Visible-Ultraviolet-X-rays-Gamma. Optical Telescopes (2 types) Optical Telescopes (2 types) 1. Refracting – 2 lenses (objective & eyepiece. Galileo invented this one. 1. Refracting – 2 lenses (objective & eyepiece. Galileo invented this one. World’s larges is the Yerkes World’s larges is the Yerkes 2. Reflecting – objective, concave mirror, flat mirror, & eyepiece. Newton invented. 2. Reflecting – objective, concave mirror, flat mirror, & eyepiece. Newton invented. World’s largest is the Hale World’s largest is the Hale Why are most telescopes on a mountain? Why are most telescopes on a mountain? Pg. 749 (fig. 28-2) Pg. 749 (fig. 28-2) Video Video Video

2 This is the study of radio waves from space… This is the study of radio waves from space… Radio Astronomy Radio Astronomy Pg. 750 Pg. 750 Radio waves travel through a vacuum. Radio waves travel through a vacuum. Detected day or night with computers. Detected day or night with computers. SETI SETI The largest single radio telescope is 300 meters in diameter. The largest single radio telescope is 300 meters in diameter. Radio Telescope Arrays are radio telescopes arranged in groups, so they act as one telescope. Radio Telescope Arrays are radio telescopes arranged in groups, so they act as one telescope. This creates an interferometry, which improves the radio image twice as much. This creates an interferometry, which improves the radio image twice as much. These are typically in a Y shape pattern. These are typically in a Y shape pattern. Video Video Video

3 The Hubble Space Telescope (HST) is the best-known telescope. It was launched in 1990 and will operate until The Hubble Space Telescope (HST) is the best-known telescope. It was launched in 1990 and will operate until Pg. 751 Pg. 751 Video Video Video Other important probes and satellites include: Other important probes and satellites include: Chandra (X-rays), Spitzer Space Telescope (wavelengths blocked by the atmosphere), Sojourner-Spirit-Opportunity (all probes on Mars). Chandra (X-rays), Spitzer Space Telescope (wavelengths blocked by the atmosphere), Sojourner-Spirit-Opportunity (all probes on Mars). Space shuttle missions are used to study microgravity and its effects on plants, animals, the growth of crystals, and other phenomena. Space shuttle missions are used to study microgravity and its effects on plants, animals, the growth of crystals, and other phenomena. The International Space Station (2000) is used to study long-term effects of space. The International Space Station (2000) is used to study long-term effects of space. Pg. 752 Pg. 752 Video Video Video

4 The Moon The last 100 years has brought a lot of new discoveries about the Moon. The last 100 years has brought a lot of new discoveries about the Moon. Sputnik I (1957) was the first satellite launched. Sputnik I (1957) was the first satellite launched. First human in space – Yuri Gagarin (1961). First human in space – Yuri Gagarin (1961). First American in space – Alan Shepard Jr. (May 1961). Pg. 753 First American in space – Alan Shepard Jr. (May 1961). Pg. 753 First on the Moon – Neil Armstrong and Buzz Aldrin (1969). First on the Moon – Neil Armstrong and Buzz Aldrin (1969). Video Video Video Most moons are much smaller than the planet they orbit. Most moons are much smaller than the planet they orbit. The Earth’s moon is the only large moon among the inner planets. Mercury and Venus have no moons at all, and the moons of Mars are just 2 tiny chunks of rock. The Earth’s moon is the only large moon among the inner planets. Mercury and Venus have no moons at all, and the moons of Mars are just 2 tiny chunks of rock. Video Video Video

5 The Moon’s albedo (light reflection) is about 7% compared to the Earth’s 31%. The Moon’s albedo (light reflection) is about 7% compared to the Earth’s 31%. Sunlight gets absorbed easily on the Moon’s surface, which is why the surface is as high as 127° C and without sunlight the surface temperature can drop to - 173° C. Sunlight gets absorbed easily on the Moon’s surface, which is why the surface is as high as 127° C and without sunlight the surface temperature can drop to - 173° C. There is no erosion on the Moon. There is no erosion on the Moon. There is no atmosphere or flowing water. There is no atmosphere or flowing water. Regions : Highlands – mountainous and heavy with craters. Maria – smooth plains. Pg. 754 Regions : Highlands – mountainous and heavy with craters. Maria – smooth plains. Pg. 754 All the craters are impact craters formed from objects hitting the surface. Pg. 755 All the craters are impact craters formed from objects hitting the surface. Pg. 755 Ejecta is the fall back material from an impact and they form long trails called rays. Ejecta is the fall back material from an impact and they form long trails called rays. Video Video Video

6 Why so many craters on the Moon and not the Earth? Why so many craters on the Moon and not the Earth? No atmosphere No atmosphere No erosion No erosion The Earth had crater impacts, but with erosion only new impacts are visible. The Earth had crater impacts, but with erosion only new impacts are visible. The Moon has a lot of silicates, breccias, and basalts. The Moon has a lot of silicates, breccias, and basalts. The Moon is most likely layered like Earth with a crust, upper mantle, lower mantle, and a core. The Moon is most likely layered like Earth with a crust, upper mantle, lower mantle, and a core. Fig (pg. 756) Fig (pg. 756) The crust, upper mantle, and core are solid. The lower mantle is partially molten. The crust, upper mantle, and core are solid. The lower mantle is partially molten. The Moon has no active volcanoes and very slight moonquakes that could rattle dishes on Earth once a year. The Moon has no active volcanoes and very slight moonquakes that could rattle dishes on Earth once a year. This causes scientists to theorize that the Moon has no tectonics. This causes scientists to theorize that the Moon has no tectonics. Video Video Video

7 The most supported theory of how the Moon formed is the impact theory. The most supported theory of how the Moon formed is the impact theory. It formed as a result of a gigantic collision between Earth and a Mars-sized object about 4.5 billion years ago. This occurred when the solar system was forming. It formed as a result of a gigantic collision between Earth and a Mars-sized object about 4.5 billion years ago. This occurred when the solar system was forming. As a result, materials from the incoming body and from Earth’s outer layers were ejected into space, where they then merged together to form the Moon. As a result, materials from the incoming body and from Earth’s outer layers were ejected into space, where they then merged together to form the Moon. Fig (pg. 757) Fig (pg. 757) Video Video Video Video Video Video

8 The Sun-Earth-Moon System It appears that the Moon, Sun, and stars are rotating around the Earth every day. It appears that the Moon, Sun, and stars are rotating around the Earth every day. For years scientists believed this geocentric view point. For years scientists believed this geocentric view point. We now know that the Earth is rotating 15° per hour. We now know that the Earth is rotating 15° per hour. A pendulum can demonstrate the rotating Earth. A pendulum can demonstrate the rotating Earth. The direction of the pendulum swinging shifts direction with the rotation of the Earth. Pg. 758 The direction of the pendulum swinging shifts direction with the rotation of the Earth. Pg. 758 We can also demonstrate the rotating Earth with the fact that flowing air and water on Earth are diverted from a a north-south direction to an east-west direction as a result of Earth’s rotation (Coriolis effect). We can also demonstrate the rotating Earth with the fact that flowing air and water on Earth are diverted from a a north-south direction to an east-west direction as a result of Earth’s rotation (Coriolis effect). Video Video Video

9 The length of day as we observe it is a little longer than the time it takes Earth to rotate once on its axis. The length of day as we observe it is a little longer than the time it takes Earth to rotate once on its axis. 365 days a year 365 days a year Leap year to compensate for this. Leap year to compensate for this. Annual changes are the result of Earth’s orbital motion about the Sun. Earth’s orbit around the Sun is ecliptic. Fig (pg. 759) Annual changes are the result of Earth’s orbital motion about the Sun. Earth’s orbit around the Sun is ecliptic. Fig (pg. 759) The Earth’s axis is tilted at 23.5°. The Earth’s axis is tilted at 23.5°. This is fixed throughout the year, so seasons occur. This is fixed throughout the year, so seasons occur. This also causes the Sun to change it’s angle and altitude in the sky. Fig (pg. 759) This also causes the Sun to change it’s angle and altitude in the sky. Fig (pg. 759)

10 The position of the Earth and Sun. The position of the Earth and Sun. Page 760  Draw and go over. Page 760  Draw and go over. Summer solstice – Sun is directly over head in the sky (at Tropic of Cancer). Occurs on June 21. Summer solstice – Sun is directly over head in the sky (at Tropic of Cancer). Occurs on June 21. The number of hours of daylight is maximum at this day in Northern Hemisphere. The number of hours of daylight is maximum at this day in Northern Hemisphere. Winter solstice – Sun is directly over head in the sky (at Tropic of Capricorn). Occurs on December 21. Winter solstice – Sun is directly over head in the sky (at Tropic of Capricorn). Occurs on December 21. The number of daylight hours is at a minimum in the Northern Hemisphere. The number of daylight hours is at a minimum in the Northern Hemisphere. The Sun never rises in the region within the artic circle in the Winter and Summer solstices. The Sun never rises in the region within the artic circle in the Winter and Summer solstices.

11 The Sun is directly overhead at the equator during the autumnal and vernal equinox. The Sun is directly overhead at the equator during the autumnal and vernal equinox. The Northern and Southern Hemispheres have equal amounts of sunlight during this time. The Northern and Southern Hemispheres have equal amounts of sunlight during this time. Sun’s position in the Northern Hemisphere. Sun’s position in the Northern Hemisphere. Fig (Pg. 762) Fig (Pg. 762) Video Video Video

12 Phases of the Moon Lunar Phases Lunar Phases Fig (Pg. 762) Fig (Pg. 762) When the Moon is between the Earth and the Sun we can’t see it because no light is reflected. This is called a new moon. When the Moon is between the Earth and the Sun we can’t see it because no light is reflected. This is called a new moon. As the Moon moves along in its orbit the amount of light reflected increases. The increasing reflected sunlight is called waxing. As the Moon moves along in its orbit the amount of light reflected increases. The increasing reflected sunlight is called waxing. When less than half of the sunlit portion of the Moon is seen this is called a waxing crescent. When less than half of the sunlit portion of the Moon is seen this is called a waxing crescent. When more than half of the sunlit portion of the Moon is seen this is called waxing gibbous. When more than half of the sunlit portion of the Moon is seen this is called waxing gibbous. Video Video Video

13 The first quarter of the Moon occurs when we see half of the sunlit side. The first quarter of the Moon occurs when we see half of the sunlit side. A full moon occurs next, in which the Earth is between the Sun and the Moon. A full moon occurs next, in which the Earth is between the Sun and the Moon. The sunlit side decreases after this. This is called waning. The sunlit side decreases after this. This is called waning. As in the waxing phases, there is a period during the waning phases when we can see more than half of the sunlit portion of the Moon. As in the waxing phases, there is a period during the waning phases when we can see more than half of the sunlit portion of the Moon. These phases are called waning gibbous and waning crescent. These phases are called waning gibbous and waning crescent. The Moon reaches a point in the waning phases in which we can see half of the sunlit portion. This is called the third quarter. The Moon reaches a point in the waning phases in which we can see half of the sunlit portion. This is called the third quarter. Fig (pg. 763) Fig (pg. 763) Video Video Video

14 Synchronous rotation – the Moon rotation is equal to it’s orbital movement. Synchronous rotation – the Moon rotation is equal to it’s orbital movement. This is why we see the same side of the Moon. This is why we see the same side of the Moon. From one full moon to the next is called a lunar month  29.5 days. From one full moon to the next is called a lunar month  29.5 days. The Moon takes 27.3 days to orbit the Earth. The Moon takes 27.3 days to orbit the Earth. Why the difference? Fig (Pg. 764) Why the difference? Fig (Pg. 764) Because the Earth’s position (angle) with the Sun has changed, thus the Moon has to travel 2.2 more days to complete a lunar month. Because the Earth’s position (angle) with the Sun has changed, thus the Moon has to travel 2.2 more days to complete a lunar month. The Moon’s gravity pulls on Earth’s surface and creates a bulge of ocean water on both the near and far side of Earth. The rotation of the Earth contributes to 2 high and low tides in a day’s time. The Moon’s gravity pulls on Earth’s surface and creates a bulge of ocean water on both the near and far side of Earth. The rotation of the Earth contributes to 2 high and low tides in a day’s time. A high tide every 12 hours & low tide every 12 hours. Draw. A high tide every 12 hours & low tide every 12 hours. Draw.

15 ` Solar eclipse occurs when the Moon passes directly between the Sun and Earth and blocks our view of the Sun. Solar eclipse occurs when the Moon passes directly between the Sun and Earth and blocks our view of the Sun. The solar eclipse can vary from a partial to a full. The solar eclipse can vary from a partial to a full. Fig (pg. 765) Fig (pg. 765) Fig Fig A solar eclipse doesn’t happen every month with each new moon because the Moon’s orbit is tilted 5° relative to the ecliptic. A solar eclipse doesn’t happen every month with each new moon because the Moon’s orbit is tilted 5° relative to the ecliptic. The closest point in the Moon’s orbit to Earth is called perigee. The closest point in the Moon’s orbit to Earth is called perigee. The farthest point is called apogee. The farthest point is called apogee. Video Video Video

16 A lunar eclipse occurs when the Moon passes through Earth’s shadow. A lunar eclipse occurs when the Moon passes through Earth’s shadow. Fig (pg. 767) Fig (pg. 767) A lunar eclipse can only occur during a full moon. A lunar eclipse can only occur during a full moon. Like a solar eclipse, a lunar eclipse doesn’t occur every full moon because the Moon in its orbit usually passes above or below the Sun as seen from the Earth. Like a solar eclipse, a lunar eclipse doesn’t occur every full moon because the Moon in its orbit usually passes above or below the Sun as seen from the Earth. Solar and lunar eclipses occur is almost equal numbers, with slightly more lunar eclipses. The maximum number of eclipses (solar & lunar), that can be seen in a year is 7. Solar and lunar eclipses occur is almost equal numbers, with slightly more lunar eclipses. The maximum number of eclipses (solar & lunar), that can be seen in a year is (last) & again in (last) & again in Video Video Video


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