Greetings fellow astrophiles!
In preparation for upcoming 2013 lecture and observing sessions, we have put together instructional brochures to help introduce the Night Sky to attendees. The second of these, entitled “How The Night Sky Moves,” is provided below in PDF format. This brochure will be available at our combined lecture/observing sessions, but feel free to bring your own copy (or the PDF on a tablet with a good red acetate cover!).
NOTE: These brochures are made better by your input. If you find a problem, have a question, or have a suggestion (bearing in mind these are being kept to one two-sided piece of paper), please contact CNYO at firstname.lastname@example.org.
How The Night Sky Moves
Why Polaris Doesn’t (Seem To) Move
“Like the Sun, the Night Sky appears to rise in the East and set in the West (which is a result of the Earth spinning from West to East).”
The Circumpolar Constellations
“Their orientations due to Earth’s rotation may change, but they are ALWAYS VISIBLE IN THE NIGHT SKY – SO LEARN THESE SIX FIRST!”
Zodiac, Ecliptic, Solstices, Equinoxes
“The constellations of the Zodiac are special because they mark the apparent path the Sun and planets take across the sky as the Earth revolves around the Sun.”
One Earth Day vs. One Earth Rotation
“There are 24 hours in a day, but the Earth takes 4 minutes less than 24 hours to make one full rotation.”
Constellation Movement By The Hour
“With 24 hours in a day, the sky turns 15 degrees (1/24th of 360 degrees) per hour. During a 4-hour observing session, circumpolar constellations will then appear to move counterclockwise (East-to-West) 60 degrees – 1/6th of a circle – around Polaris.”
Constellation Movement During The Year
“After 12 months, the Earth (and our view of the Night Sky) almost returns to the same position it was the year before. Why almost?”