Astronomy 1010-H
Planetary Astronomy
Fall_2015
Day-10
Course Announcements
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SW chapter 2 – due Monday 9/21; 2pm
How is the lunar observing going?
How is the sunset/sunrise observing going?
1st Quarter night – Mon. 9/21 -7:30pm – on campus
Exam 1: Mon. Sept. 21
This Week: APSU-OUR: Research & Creative Activity
Week. Events in the library 2:30-3:30 every day.
Spacecraft Reports
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Chantal H. – New Horizons
Ashley G. – Dawn
Mahalia S. – NuStar
Tristan C. – Mangalyaan
Spencer B. – Voyager
Arielle P. – Curiosity Rover
Lars A. – Cassini
Sarah E. – Rosetta
John M. – Mars Phoenix
Jordan T. – Galileo
Rashun B. – Apollo Missions
The Cycle of Lunar Phases
The moon does rotate.
The moon takes the same amount of
time to complete one rotation as it does
to complete one orbit
The orbital period is not the
same as the cycle of phases
The Orbital Period is the Sidereal Month:
27.32 days
Cycle of phases:
The synodic month
29.53 days
Lecture – Tutorial
Cause of Moon Phases: pg 81
 Work with a partner!
 Read the instructions and questions carefully.
 Discuss the concepts and your answers with one
another.
 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.
i_Clicker Question
 ClassAction: Questions:
 Lunar Cycles: Phase Evolution; option 1
Lecture – Tutorial
Predicting Moon Phases: pg 85
 Work with a partner!
 Read the instructions and questions carefully.
 Discuss the concepts and your answers with one
another.
 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.
i_Clicker Question
 ClassAction: Questions:
 Lunar Cycles: Identify Lunar Position from Phase
i_Clicker Question
 ClassAction: Questions:
 Lunar Cycles: Phases Visible; option 1
Stuff in Chapter 2
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Coordinates
Position
Daily Motion (spin of Earth on its axis)
Visibility of the sky
Year Motion (Earth orbits the Sun)
Seasons (tilt of the Earth’s axis)
Precession of the equinoxes
Motion and phases of the Moon
Eclipses
Eclipses!
 Three types of solar
eclipses:
• Total: The Moon
completely blocks
the Sun’s light.
• Partial: Only part
is blocked.
• Annular: The Sun
appears as a bright
ring surrounding the
Moon.
Solar Eclipses
 Solar eclipses happen at new Moon.
 Moon passes between Earth and the Sun.
 Only a small portion of Earth can witness
each one.
 The part of the Moon’s shadow you are in
determines which type of solar eclipse you
see.
 Umbra: Total or annular.
 Penumbra: Partial.
 Lunar eclipses happen at full
Moon.
 Earth is between the Sun and the
Moon.
 Visible over a wider area of Earth.
 Last a lot longer than solar
eclipses.
 Eclipses do not occur every month because
the Moon’s orbit is tilted 5.2° with respect to
Earth’s orbit around the Sun.
 Intersection: line of nodes.
Lunar Eclipse: Earth passes
directly between the Sun & Moon
The Total Lunar Eclipse
Next one is April 15,
2014 for North
America
A Solar Eclipse requires much
more precise alignment
The Moon’s shadow is not large
enough to cover the Earth
Partial eclipses are more
common than total eclipses
Annular
Eclipses
occur when
the Moon is
at or near
apogee
Solar Eclipses take hours to
develop but last only minutes