1 phases of the moon the phases of the moon are the variations in the moon’s appearance as the...
TRANSCRIPT
![Page 1: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/1.jpg)
1
Phases of the Moon• The Phases of the Moon
are the variations in the Moon’s appearance as the Moon orbits the Earth.
• They are due to the changing Sun-Earth-Moon angle through each month.
• The following is the cycle of lunar phases: new, crescent, first quarter, gibbous, full, gibbous, third quarter, crescent, new
![Page 2: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/2.jpg)
2
Moon Phases• The Moon orbits
the Earth in about one month (29.5 days)
• Over one orbit the appearance and rise and set times change with the cycle of Lunar Phases.
• The figure is not to scale
![Page 3: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/3.jpg)
3
Light & Dark• We only see the Moon because
sunlight reflects off its surface.
• At any one time, half the Moon is always lit and half is in darkness.
• The amount of the illuminated half we see from Earth depends on the position of the Moon in its orbit
• The time of day the Moon is visible also depends on its phase. How the Earth and Moon would
look high above Earth’s North Pole.The figure is not to scale.
![Page 4: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/4.jpg)
4
Example: Observing the Moon• Between January 23-25, 2004,
at dusk, the Moon was visible in its waxing crescent phase.
• The first night it appeared close to the Sun. Subsequent nights it appeared higher in the sky (farther from the Sun) and the lit portion appeared to be growing larger.
• What do you think you would see the next night? How about a week later?
![Page 5: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/5.jpg)
5
Lunar Phase Terms
We can only see the half of theMoon above and to the right of thediagonal line drawn on the Moonin the figure above.
• The cycle of Lunar Phases starts at the New Moon.
• At New Moon the Moon is not visible to us on Earth.
• From New Moon to Full Moon the illuminated fraction of the Moon we see from Earth grows. It is said to be waxing.
• After Full Moon the fraction of the illuminated Moon visible from Earth shrinks. It is said to be waning.
![Page 6: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/6.jpg)
6
The Cycle of Lunar Phases• The Lunar cycle is
split into quarters– New Moon
– 1st Quarter
– Full Moon
– 3rd (or Last) Quarter
• Since the whole cycle lasts about a month each quarter lasts about a week.
![Page 7: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/7.jpg)
7
As you view the moon from different directions (relative to the Sun) its appearance changes.
![Page 8: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/8.jpg)
8
crosses meridianat sundown
crosses meridianat about 9:00 pm
crossesmeridianat midnight
crossesmeridianat about 3:00 am
crosses meridianat dawn
crosses meridianat about 9:00 am
crossesmeridian at noon
crosses meridianat about 3:00 pm
sunlight
sunlight
![Page 9: 1 Phases of the Moon The Phases of the Moon are the variations in the Moon’s appearance as the Moon orbits the Earth. They are due to the changing Sun-Earth-Moon](https://reader035.vdocument.in/reader035/viewer/2022072010/56649db55503460f94aa6e32/html5/thumbnails/9.jpg)
9
The Lunar Phases Web Tool• This is an interactive tool
that helps illustrate how – the time of day, – the phase of the Moon
and, – the position of the Moon
in its orbit are all related to one another.
• The time that is used in this tool is only an average 6 PM represents sunset, 6 AM represents sunrise, etc.
“Lunar Phases Web Tool” located at
http://www.calvin.edu/~lmolnar/moon/index.html