Astronomy 1010-H
Planetary Astronomy
Fall_2015
Day-7
Course Announcements
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Read Chapter 2
How is the lunar observing going?
How is the sunset/sunrise observing going?
This week: Dark Night Observing on Thur. 9/10
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1st Quarter night – Mon. 9/21 -7:30pm – on campus
Exam 1: Fri. Sept. 18 or Mon. Sept. 21
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This weekend: Thurs. - Sat. – Riverfest
Definitions & Terms -1
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Cat: An animal that was once revered as a God by the
Egyptians. Cats have not forgotten this.
Orbit: The path of one body (e.g. a planet) around another
(e.g. the Sun in our solar system).
Orbital Period: The time it takes an orbit to occur.
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. –
Sarah E. –
John M. –
Jordan T. –
Rashun B. – Apollo Missions
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
Nightly Motion of the Stars
Imagine looking
toward the North.
What do stars
appear to do over
the course of an
evening?
Nightly Motion of the Stars
Looking North: Stars
appear to move counterclockwise around the
stationary North Star
(Polaris) – we call these
circumpolar stars.
Earth’s rotation causes the Sun, Planets,
Moon and stars to appear to move when
viewed from Earth
Photo: Dr. Spencer Buckner
Nightly Motion of the Stars
Celestial Sphere Rotation
Star B
2
Star A
1
2
Celestial Sphere
Celestial Sphere
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1
4
3
4
Celestial Sphere
Rotation
Figure 2
Horizon
Circumpolar Stars
 Circumpolar stars seem to move counter-clockwise
around the stationary North Star.
 These constellations and stars are visible any night of the
year in the NORTHERN sky because they never rise or set!
 Examples: Ursa Major, Ursa Minor, Draco, Cepheus, and
Cassiopeia
Tutorial: Motion – p.3
 Work with a partner
 Read the instructions and questions carefully
 Discuss your answers with each other.
 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
Concept Quiz
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Imagine that from your current location you
observe a star rising directly in the east. When
this star reaches its highest position above the
horizon, where will it be?
A.
B.
C.
D.
high in the northern sky
high in the southern sky
high in the western sky
directly overhead
3-minute Essay
How long did this picture
take and WHY do you
think that?