SOLAR SYSTEM Sun, Mercury, Venus, Earth, Earth’s Moon, Mars, Jupiter, Saturn, Uranus & Neptune.
Lecture 11 Moon Phases and Eclipses Full Moon near Saturn The Moon will be full on Sunday, 4/17/11...
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Transcript of Lecture 11 Moon Phases and Eclipses Full Moon near Saturn The Moon will be full on Sunday, 4/17/11...
Lecture 11
Moon Phases and Eclipses
Full Moon near Saturn
The Moon will be full on Sunday, 4/17/11 so
on Saturday and Sunday night it will
be near Saturn, which reached opposition
last week and, like the full Moon, is on the opposite side of the
sky as the Sun.
In each phase of the Moon, how much of the Moon is lit up by the Sun? Half the Moon is always
lit by the Sun
Except . . .
When the Earth’s shadow hits the Moon we have a …….
Lunar Eclipse
Eclipses occur ONLY when the Moon crosses the plane of Earth’s orbit around the Sun AND
ONLY during the NEW or FULL phases
Lunar Eclipse
• When Earth blocks most of the sunlight from illuminating the Moons surface for several hours when in the full moon phase
When the Moon’s shadow hits the Earth, we have a ….
Solar Eclipse
Solar Eclipse
Annular Eclipse
Partial Eclipse
Total Eclipse
Eclipses occur ONLY when the Moon crosses the plane of Earth’s orbit around the Sun AND
ONLY during the NEW or FULL phases
Which positions cause which eclipses
• When the ______ is in the _____ phase and is directly in line with the _____ and the ____ , you get a ______ eclipse?
• When the ______ is in the _____ phase and is directly in line with the _____ and the ____ , you get a ______ eclipse?
Moon fullEarth Sun
MoonEarth Sun
new
lunar
solar
When the full Moon is rising in the East, what is the Sun always doing?
The Sun is always setting in the West.
Therefore the Sun and Moon are exactly ________ degrees apart…try a human animation if you are having difficulty visualizing this.
The only exception is …
180
…if there is a lunar eclipse, with the Moon crossing the line of nodes.
How are the motions and positions of Earth and the Sun connected to what
happens on Earth?• Earth’s rotation on its axis determines the
length of the day.
• Earth’s orbit around the Sun determines the length of the year.
• The tilt of Earth’s rotational axis with respect to the plane of Earth’s orbit causes the seasons.
The changing phases of the Moon originally inspired the concept of the month
Watch Movie at:http://antwrp.gsfc.nasa.gov/apod/image/9911/lunation_ajc.gif
Moon Phase Names• New Moon• Waxing Crescent• First Quarter• Waxing Gibbous• Full Moon • Waning Gibbous• Third Quarter• Waning Crescent
The Causes of Moon Phases
• Think to yourself about the answer to this question:
What causes the phases of the Moon?
Take out a piece of paper and quickly write out a brief answer.
How long does it take to complete the full cycle of Moon Phases?
A. About a dayB. About a weekC. About a monthD. About a yearE. None of the above
Check your answer with your partner!
Solar Period vs. Sidereal Period of the Moon
Synodic (Solar) vs. Sidereal Periodof
the Moon
Synodic Period is 29.53 days, Moon rotates to the orange line, more than 360 degrees; back to the same phase (new moon) as leftmost image.
Sidereal Period is 27.32 days, Moon rotates to the purple line (which should be parallel to the leftmost red dotted line), 360 degrees; not back to New Moon - same phase as leftmost image
Right now our Moon is just…
What phase is our Moon in right now?
Just a day past First Quarter
Discuss light fills in from the right-ish side.
http://www.clarkplanetarium.org/pages/nightSky
http://meteorshowersonline.com/lyrids.html
http://yasirlioneljordan.blogspot.com/2011/04/moon-phases-2011-february.html
Lunar Calendar
Let’s Watch some Moon Phase Animations!
Pay attention to where the Moon, Sun and Earth are located and how the Moon appears from Earth at each of these positions.
Look at how much of the Moon is illuminated when at each position.
Look at which side of the Moon is illuminated when at each position.
Animation
ZOOM IN
Prepare for Human Animation! Get volunteers! Look at tidal locking.
Discuss plane of Moon’s orbit and angle.
http://www.sumanasinc.com/webcontent/animations/content/moonphase.html
What is a monthly cycle
& what is a daily cycle?
Label the daily times and how
the Moon phases are
broken up over time. Name the phases of the Moon that are shown.
Discuss rising and setting.
Although the Moon is always
½ lit by the Sun, we see
different amounts of the lit portion from
Earth depending on
where the Moon is
located in its month-long
orbit.
1) How many phases shown in the picture will the Moon go through in one day?
2) How long does it take the Moon to complete one orbit? How many of the phases will the Moon have gone through in this time?
3) How long does it take the Earth to complete one rotation? How far will the Moon have moved?
4) How much of the Moons total surface is illuminated when it is in the New Phase? Full Phase?
5) How much of the illuminated surface of the Moon is visible from Earth when it is in the First Quarter Phase, Full Phase?
6) What time is it when the Waxing Gibbous Phase is highest in the sky, Rising? Setting? What phase will it be in one week later….see next slide for answer. SKIP RED PORTION.
A Moon Phase is highest in the sky at 9 pm today. What phase will the Moon have in three weeks after today?
Lecture Tutorial: Cause Moon Phases
• Work with a partner!• Read the instructions and questions carefully.• Discuss the concepts and your answers with one
another. Take time to understand it now!!!!• Come to a consensus answer you both agree on.• If you get stuck or are not sure of your answer, ask
another group.• If you get really stuck or don’t understand what the
Lecture Tutorial is asking, ask one of us for help.
A few more resources you might enjoy!
Animations:
more complex demo. http://jove.geol.niu.edu/faculty/stoddard/JAVA/moonphase.html
Useful information and tables as covered in class:http://home.hiwaay.net/~krcool/Astro/moon/moonphase/Gives information on the different moon phases and the times of day when they are visible.