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The Moon. Chapter 25. Total Lunar Eclipse February 20, 2008 Peak 10:26 pm. Viewing Area. Next Total Lunar Eclipse: December 21, 2010. Next Total Solar Eclipse: August 1, 2008. http://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2010-Fig02.pdf. Partial Lunar Eclipse June 26, 2010.
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The Moon Chapter 25
Viewing Area Next Total Lunar Eclipse: December 21, 2010 Next Total Solar Eclipse: August 1, 2008
http://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2010-Fig02.pdf Partial Lunar Eclipse June 26, 2010
How Long Does it Take to Get There? • a. THE FLYING TIME FROM THE EARTH TO THE MOON can be expressed as a three-week, nonstop ride in a jet airplane, traveling at 500 miles per hour. It would take approximately one school day to fly across the continental United States at the same speed. • b. TRAVELING TO THE MOON BY CAR at 55 miles per hour for 12 hours a day would require one year’s worth of time to complete the trip. Of course, one would have to return which would require an identical amount of time. A student could miss two full years of school on a round trip to the moon. Any volunteers...? http://www.astronomy.org/programs/moon/moon.html
Apollo 11 Crew: This is the most famous picture taken by NASA of the three-member crew that flew in Apollo 11, the first mission where people walked on the moon. Everyone knows that Neil A. Armstrong was the first astronaut to walk on the moon, but do you know his location in the picture? The astronaut sitting on the right is Buzz Aldrin, the second person to walk on the moon. The standing astronaut is Michael Collins. He remained in the Command Module while Buzz and Neil walked. Yes, Neil is seated on the left with the biggest smile.
A. The moon is a satellite ( a smaller body orbiting around a larger one) The Moon: An Introduction 1. Luna- Latin from moon 2. Diana, or Luna, Roman goddess of the Moon, animals, and hunting (earth’s moon).
Name the three astronauts that first landed on the moon. • Draw the shape of the moon as seen this past weekend. Neil Armstrong, Buzz Aldrin, Michael Collins
B. Physical Properties of the Moon • Size a. Diameter: 2,160 miles (3,476 kilometers) b. Compared to Earth Diameter of: Moon = 2,160 = 0.27 or about ¼ Earth 8,000 c. Scale of Size
2. Gravity a. The Moon has 1/6 the gravity of Earth. b. The Earth is 81 times more massive (weight) than the moon. The moon’s average density is 3.3 g/cm3 and the Earth’s average density is 5.5 g/cm3. A person standing on the moon would feel as if his or her weight had decreased by 5/6. And if that person dropped a rock, the rock would fall to the surface much more slowly than the same rock would fall to Earth.
3. Atmosphere a. The moon has a very limited atmosphere (aka: exosphere). b. On the moon, the sky always appears dark, even on the bright side.
4. Temperatures a. +260 degrees F (+127 degrees C) on the lighted side. b. -280 degrees F (-173 degrees C) on the dark side. c. These large temperature extremes or differences exist because the moon has very little atmosphere.
C. Lunar Topography Crater- circular hollows on moon’s surface -caused by impacts from meteoroids/asteroids Rays- cracks that radiated outward from craters - can reach hundreds of kilometers in length Tycho Crater
Maria- Latin for seas - Large dark areas on moon caused by volcanic activity. - Higher density of surrounding areas (mascons). - Basalts Sea of Serenity Sea of Rains
Highlands- usually found on the edges of maria - Lower density. - Anorthosite (igneous) Apennine Mt. & Caucasus Mt.
Regolith- loose rock material (small rocks, sand, dust) - Contains no water or organic materials (NOT soil)! - Depths of 2-20 meters. Buzz Aldrin’s footprint in Regolith
D. The Moon’s Revolution 1. Period of Revolution a. 27 1/3 days OR b. 1 month 2. The moon revolves around the Earth in an elliptical orbit, and Earth is at one foci. 3. This causes the moon’s apparent diameter to change in a cyclic manner.
The Moon month: Sidereal Month= the time the Moon takes to complete one full revolution around the Earth with respect to the background stars. However, because the Earth is constantly moving along its orbit about the Sun, the Moon must travel slightly more than 360° to get from one new moon to the next. 27.3 days (27 d 7 h 43 min 11.5 s) http://www.sumanasinc.com/webcontent/animations/content/sidereal.html Synodic Month= the time it takes for the Moon to complete one cycle of phases. That is, the time between successive new moons. 29.5 days
E. Phases of the Moon 1. Caused by the orbit (revolution) of the moon and the rotation of Earth. 2. Our Earth view of the changing phases is the view of the sunlit portion and the dark portion of the moon.
3a & b. Phases of Moon as Viewed from Earth and Space. Sun’s Rays
c. (1) Waning- the decreasing of the moon’s visible surface; from full moon to new moon. Light on left = leaving c. (2) Waxing- the increasing of the moon’s visible surface; from new moon to full moon. Wax on right!
F. The Near and Far Sides of the Moon 1. The Near Side- the side of the moon that always faces Earth. It is nearly half highlands and half maria. 2. The Far Side- the side of the moon that never faces Earth. It is mostly highlands/craters. 3. The same side of the moon (the near side) always faces Earth because: the period of the moon’s rotation and revolution are nearly equal. The dark side is NOT always dark! 27.3 days Rotation = Revolution = 27 days 8 hours
Far Side Near Side
Picture of Mare Imbrium with the craters Plato and Cassini, the Alpine Valley, Mt. Pico and Mt. Piton
Moon Phases Animation http://www.youtube.com/watch?v=rp7FQXSrmdQ
What is moonrise time? Sunset
What is the phase? Waxing Gibbous
What is the name of the next phase? Waning Crescent
What is the phase? Waxing Crescent
What is the phase? Full Moon
What is the phase? Waning Crescent
What is the phase? Waxing Quarter or First Quarter
What is the name of the next phase? New Moon
What is the phase? Waning Quarter or Last Quarter
What is the moonset time? Midnight
What is the phase? Waning Gibbous
On a particular evening a business man decides to work extra hours at his office in London because his wife went out with her friends. After some hard work he opens the curtains of his office and looks outside (see the picture), but immediately he gets in panic. Why? The moon is a waning crescent. The waning crescent is only in the sky in the northern hemisphere from about 3 am (rises) to 3 pm (sets). This moon just rose. The business man stayed at the office VERY late!
Tides http://www.classzone.com/books/earth_science/terc/content/investigations/es2406/es2406page01.cfm A tide is the rise and fall of ocean surface levels due to the gravitational pull from the Moon and Sun.
Spring and Neap Tides PPT http://www.geo.umn.edu/courses/1006/fall2005/handouts/Tides.pdf Spring Tide: A tide of large range occurring during the full and new moon phases. (moon and Sun aligned in a straight line) Neap Tide: A tide of small range occurring during quarter phases of the moon. (moon and Sun at right angles to one another)
Eclipses • Although the Sun is about 400 times larger than the Moon, it is also about 400 times further away. – Both appear to be about ½ degree across. – As a result of this coincidence, the Moon can completely cover the Sun, producing a total solar eclipse. Solar Eclipse = moon covers the Sun and casts a shadow on Earth (new moon phase) Lunar Eclipse = Earth casts a shadow on the moon (full moon phase)