AST 180 INTRODUCTION TO ASTRONOMY
STUDY GUIDE--EXAM 1 FALL 2007
1. How is the scientific method used to advance knowledge?
Part of the scientific method is to create hypotheses.
By testing the hypotheses, a scientist is able to determine whether or not a certain experiment
works, therefore expanding the amount of information known about the subject area. Knowledge is gained through experiments and hypotheses,
which is the scientific method. The scientific method also helps to determine between science and pseudoscience.
2. What is the difference between astrology and astronomy?
Astrology is a pseudoscience whereas astronomy is science, specifically the study of the universe: its properties, components, evolution
3. How do astronomers obtain information about the distant planets, stars, and galaxies?
Through observation; using technology such as telescopes and spacecraft, as well as physically exploring nearby places in space
4. Why do we study astronomy?
It tells us about time units (days, months, years); it exemplifies how we “fit in” and how events elsewhere can affect us; it offers historical insight as to
where we came from; explains phenomena affecting earth (seasons, tides, etc); humans are curious; it is a means of navigation
5. What are astronomical units, light-years, and parsecs? In what part of the universe is each primarily used?
AU = the average distance between the earth and the sun (1.5 X 10
km or 9.3 X 10
inside our solar system
; LY = the distance that light travels
in one year (~10
km or 6 X 10
outside solar system
; pc = 3.09 X 10
km or 3.26 LY
outside solar system
6. What are constellations?
Constellations are groups of stars that form patterns in the sky that take up a certain sector of the celestial sphere
7. How many constellations are there?
There are 88 official constellations
8. What are asterisms? What are some examples?
Asterisms are groupings of stars that are not officially recognized as constellations by the IAU. Examples include the big dipper, the little dipper, and
the summer triangle.
9. What is the celestial sphere?
The apparent sphere of the night sky; the hypothetical sphere whose radius is centered on the observer
10.What are the celestial sphere equivalents of the north pole, south pole, equator, latitude, and longitude?
North Pole = north celestial pole; South Pole = south celestial pole; equator = celestial equator; latitude = declination; longitude = right ascension
11.What object marks the north celestial pole? How does its elevation in the sky change as one’s latitude changes?
Polaris / the North Star marks the north celestial pole. It’s elevation in the sky equal to the declination of any given position. At the North Pole, it is
directly over head (90º) and at the equator, it is on the horizon (0º)
12.How do the stars appear to move throughout the course of the night?
Throughout the night, stars appear to move westward (rise in the east, set in the west)