The Sky From EarthThe Sky From Earth

Let’s Step OutsideLet’s Step Outside

Where are the stars?

What direction are we facing?

SunsetSunset

What direction are we facing now?

NightNight

TimeTime

Important LocationsImportant Locations

Meridian- An imaginary line through Zenith extending from North to South.

Zenith- The point on the Celestial Dome that is directly overhead.

Celestial Equator- The projection of the Earth’s equator onto the Celestial Sphere.

I Need a New LatitudeI Need a New Latitude

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A long exposure photograph shows A long exposure photograph shows the stars moving in perfect circles the stars moving in perfect circles around zenith. (the stars neither around zenith. (the stars neither rise or set). You are:rise or set). You are:

A.A. In Orbit In Orbit

B.B. At the Earth’s equator At the Earth’s equator

C.C. At one of the Earth’s poles At one of the Earth’s poles ..

D.D. At Gerry’s House At Gerry’s House

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A long exposure photograph shows A long exposure photograph shows the stars are rising and setting the stars are rising and setting perpendicular to the horizon and perpendicular to the horizon and traveling in large arcs.traveling in large arcs.

A.A. In Orbit In Orbit

B.B. At the Earth’s equator At the Earth’s equator

C.C. At one of the Earth’s poles At one of the Earth’s poles ..

D.D. At Gerry’s House At Gerry’s House

I Hate WinterI Hate Winter

The Sun’s MotionThe Sun’s Motion

Solstice/Equinox etc.Solstice/Equinox etc.

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Stars that can be seen all year are:Stars that can be seen all year are:

A.A. Near the Celestial Poles Near the Celestial Poles

B.B. Near the Celestial Equator Near the Celestial Equator

C.C. Near the Sun. Near the Sun.

D.D. No stars can be seen all year. No stars can be seen all year.

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At Summer Solstice, the direction of At Summer Solstice, the direction of sunsets is:sunsets is:

A.A. Directly West Directly West

B.B. Directly East Directly East

C.C. North of West or East North of West or East

D. D. South of West or EastSouth of West or East

SeasonsSeasons

What causes the What causes the seasons?seasons?

SeasonsSeasonsWhy does the Earth’s tilt matter?Why does the Earth’s tilt matter?

Moon: The Dark Side of Moon: The Dark Side of thethe““There is no dark side There is no dark side

of the moon really…of the moon really…””

EclipsesEclipses

What causes a solar What causes a solar eclipse?eclipse?

The Moon blocks the Sun.The Moon blocks the Sun.

EclipsesEclipsesPartialPartial Eclipse Eclipse

In the In the penumbrapenumbraTotal Total EclipseEclipseIn the In the umbraumbra

EclipsesEclipsesShouldn’t there be one every Shouldn’t there be one every

month?month?The Moon’s orbital plane is The Moon’s orbital plane is tilted 5tilted 5oo with respect to the with respect to the

eclipticecliptic