As we look toward the sky, we notice the positions of the sun, moon, stars and
planets all change over time. We understand that these apparent motions are
due to the motions of the Earth. The earth's rotation on its axis is responsible
G E T T I N G S TA R T E D
Starry Night College
Mary Lou Whitehorne
Foreword by David H. Bradstreet, Ph.D
Professor of Astronomy & Physics
Eastern University, St. Davids, PA US
This activity introduces the concept of universal time and how it relates to local time. Also introduced are
different means of expressing angular and time measurements. By the completion of this unit the student should
be able to:
Astr 152 online class study note
Name: yue hu. Class #16198 spring 2016
2016. 2.5 chapter 1 and chapter 2 : INTRODUCTION AND SCALE OF THE UNIVERSE
Astronomical Unit (AU) - Sun-to-Earth distance and Light Year - distance light
travels in 1 year. 1 light ye
Fraction of Illuminosity:
Between 0% and 50%
Between 50% and 100%
Between 100% and 50%
Between 50% and 0%
As the earth revolves around the Sun, we see the Sun appear to move through the constellations.
The apparent path of the Sun on the celestial sphere is called the ecliptic.
Because the Earth's axis of rotation (which determines the locatio
Chapter1 : what is the sun's approximate physical diameter?
A. 1390000km B. 14900000km C. 1400000km D. 150million km
Chapter2: 1. An imaginary circle around the sky directly above the Earth's
equator. It is always 90 degrees from the poles( B ).
Where is the Sun in relationship to a planet's orbit?
a. At the center of the orbit.
b. Along the ellipse itself.
c. Off center along the long axis of the orbit.
d. Off center along the short axis of the orbit.
Answer: off center al