The following questions are based on an activity called Desktop Stars, which you will be doing in science class. If you haven’t studied Astronomy, you probably won’t know the answers to most of these questions–but give them a try anyway! (Good news: you won’t be graded!)
Part 1: Measuring the distances of objects in the universe: How far away are they? The Inverse Square Law
1. Astronomers are seeking answers to many questions about the universe. What are two questions that astronomers are trying to answer?
2. Name three "tools" that astronomers use to learn about galaxies.
3. How is it possible to measure the distance of objects in the universe?
4. What is the difference between a "luminous" light and a "bright" light?
5. What is the inverse square law? How is it used?
Part 2: What are stars made of? Light and Spectra
1. What is the name of the star that is nearest to earth?
2. What do stars emit that makes it possible for astronomers to study them from so far away?
3. What does a spectrometer measure?
4 Draw a picture of a spectrum and explain what it is.
5. How can astronomers identify the elements (such as helium, hydrogen, oxygen) found in galaxies that are millions of light years from earth?
Part 3: Objects in the universe: How fast are they moving?
1. What do sound and light both have in common?
2. How does an object’s wavelength change as it moves closer? farther away?
3. What is the Doppler effect? Can you give an example from everyday life to explain it? (Use words and/or a drawing to explain your example.)
4. What do astronomers observe about the wavelengths of light as they get longer? What happens to the spectrum?
5. What is a supernova? By comparing two supernovae, how can we estimate the age of the universe?