The Moon Copyright Antonio Cidadao. Used by permission.
Animation Shows: The complete cycle of phases Apparent size of the Moon's disk changes as its distance from Earth varies (the closest and farthest points do not always occur at the same phases, however). One side of the Moon always faces Earth
I. Moon Names Called Luna by the Romans Selene and Artemis by the Greeks Closest astronomical object to Earth Earth/Moon forms almost a double planet for no other planet has a satellite as large in comparison to the size of the planet.
II. Moon Phases http://www. earth. uni Daily changes in the Moon's appearance Occur for 2 reasons: 1. Moon is seen due to reflected sunlight 2. Moon is in orbit around Earth Waxing- Moon changes from New Moon to Full Moon, increasing in the amount of reflected light seen night after night Waning - Moon changes from Full Moon to New Moon, decreasing in the amount of reflected light seen night after night
A. New Moon "Rises at dawn, sets at dusk" The Moon's non-illuminated side is facing the Earth. The Moon is not visible (except during a solar eclipse).
B. Waxing Crescent The Moon appears to be partly but less than one-half illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is increasing. Visible during the day
C. Waxing Quarter (1st quarter) "Rises at noon, sets at midnight" One-half of the Moon appears to be illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is increasing. Can be seen during the day The dividing circle between the light side and the dark side is called the terminator.
D. Waxing Gibbous The Moon appears to be more than one-half but not fully illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is increasing.
E. Full Moon "Rises at dusk, sets at dawn“ The Moon's illuminated side is facing the Earth. The Moon appears to be completely illuminated by direct sunlight.
F. Waning Gibbous The Moon appears to be more than one-half but not fully illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is decreasing.
G. Waning Quarter (3rd quarter) “Rises at midnight, sets at noon" One-half of the Moon appears to be illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is decreasing.
H. Waning Crescent The Moon appears to be partly but less than one-half illuminated by direct sunlight. The fraction of the Moon's disk that is illuminated is decreasing. Test your knowledge of Moon Phases with this Shockwave game http://www.spaceday.com/conmgmt/index.php?option=displaypage&Itemid=156&op=page&SubMenu=
Daytime Moon Phases Moon between Earth & Sun can be seen in the daytime sky Lit side of Moon faces away from Earth during a New Moon
Nighttime Moon Phases Moon opposite Earth from the Sun is seen mostly in the nighttime sky Lit side of Moon faces Earth during Full Moon
III. Motions of the Moon Revolves around Earth from west to east (counter clockwise) in an elliptical orbit Revolution rate around Earth 27.3 days Rotates on axis once every 27.3 days Same side of Moon always faces Earth because rotation rate = revolution rate http://jove.geol.niu.edu/faculty/stoddard/JAVA/moonphase.html http://www.brainpop.com/science/space/moon/index.weml
What moon phase comes after Wanning Gibbous? A. Last Quarter B. 1st Quarter C. Full Moon D. Waxing Gibbous
How many days does it take the moon to rotate? A. 29.5 days B. 30 days C. 27.3 days D. 1 days
Which of the following means the amount of reflected light seen is increasing from night to night? A. Waxing B. Waning
Lunar Month/Lunation Complete cycle of phases Ex. Full moon to next full moon Takes 29.5 days Moon takes 2 days to catch up with Earth’s advance around the sun http://cygnus.colorado.edu/Animations/lunar2.mov
Moon Rise Times The Moon moves 130 along its orbit each day In 24 hrs the Moon has not returned to the same spot in our sky because the Earth has been moving in its revolution around the Sun. Moonrise & Moonset is 50 minutes later each day. a. Perigee - point in the Moon's orbit when it is closest to Earth b. Apogee - point in the Moon's orbit when it is furthest from Earth
IV. Apparent Size Comparison The Sun is approximately 400 times the size of the Moon Both appear similar in size in the sky because the sun is 400 times further away.
V. Eclipses The Causes: Revolution of the moon causes eclipses Moon doesn’t revolve in the same plane as Earth Occurs when Earth or the Moon blocks the sunlight reaching the other Can only occur when the Sun, Moon, & Earth are perfectly in line http://www.sun-sentinel.com/graphics/science/eclipse.htm Dates of Lunar Eclipses http://www.earth.uni.edu/~morgan/astro/course/Notes/lunareclipses.html
The angle between the Earth's orbit & the Moon's orbit is 50 Means the Moon is sometimes above the Earth's shadow and sometimes below it by 50 Determines whether a solar or lunar eclipse occurs or a New or Full Moon instead.
A. Solar Eclipse When the moon moves directly between the sun and Earth Moon casts a shadow on part of the Earth. Only people within the narrow band of the umbra see a full Solar Eclipse
Solar Eclipse Cont’ Occurs only at New Moon 3 Types of Solar Eclipses Umbra – area of total shadow; person within it sees a total eclipse Penumbra – area of partial shadow; person within it sees a partial eclipse 3 Types of Solar Eclipses Total Partial Annular
1. Totality The short part of an eclipse when the moon entirely blocks the Sun. Totality usually lasts for just a few minutes (no more than 8 minutes in any one location on Earth).
Total Solar Eclipses (Path of Totality )
Solar Eclipse Cont’ The longest solar eclipses occur when: Earth is at aphelion (farthest from the Sun, making the solar disc smaller) And the Moon is at perigee (closest to the Earth, making the Moons apparent diameter larger).
2. Partial Solar Eclipse Moon only covers part of the solar disc.
Annular Eclipse Animation by Kevin McMahon TR South Class of '05 Moon at apogee, the shadow from the umbra doesn’t reach Earth. Observers at the center see the sun as a thin, bright ring around the moon.
B. Lunar Eclipse Earth’s shadow falls on the moon; Moon becomes darker and may appear red in color because the light from the sun is refracted around the Earth Only the longest wavelengths (red & orange) make it.
Lunar Eclipse Cont’ Anyone on the nighttime side of Earth can see a Lunar Eclipse. Occurs only at Full Moon Full Moon is usually above or below the Earth's umbra so no eclipse occurs
VI. Tides Daily rise & fall of the ocean waters On avg. tides rise 50 minutes later each day. During New moon & Full moon tides are large During Quarter moon phases tides are small Approximately 6 hrs & 12 minutes between high & low tide
A. Direct High Tide Bulge in ocean on the side of the Earth near the moon Reason: Gravity is stronger when objects are closer together. Water on Earth is pulled more than Earth because it is "closer" to the moon
B. Indirect High Tide Bulge in ocean on the side of Earth furthest from the moon. Why? Earth's center is nearer the moon than the water on the far side of Earth. Earth is pulling away from the water causing the bulge. Low tide occurs in areas that lie in between the two high tides.
A. Spring Tides high tides are very high, and low tides are very low Occur during New and Full Moon phase Occur twice a month Sun, Moon & Earth are in alignment Gravitational effects of the Sun & Moon are added together Moon at Perigee- tidal effect is greater especially during a New or Full Moon
B. Neap Tides High tides are not very high and low tides are not very low Occur during Quarter Moon phase Occur twice a month Sun and Moon are at 900 angles to Earth
C. Tidal Range - the difference in lebetween high tide and low tide Ex C. Tidal Range - the difference in lebetween high tide and low tide Ex. Bay of Fundy, Nova Scotia has a range of 20m D. Hydrographer - scientist who studies tides
Moon Time Waxing Crescent Waxing Gibbous 1st Quarter New Moon Full Moon 3rd Quarter Waning Gibbous Waning Crescent
6 PM 9 Pm 3 PM 12 AM 12 PM 9 AM 3 AM 6 AM
Set Moon Rise W Phase E S