What is the reason why we have seasons on the Earth? Give as much detail as you can in your own words, but be careful...if you include a misconception, the score is 0.
We observe a distant object in space and see that the spectral lines for hydrogen in the object's light appear at a shorter wavelength than normal. What does this tell us about the object and why? What is this effect called? Give as much detail in your own words as you can.
What two observations did Galileo make that supported a heliocentric model? Explain in your own words why they did not fit a strictly geocentric model.
Identify and describe the three main methods that are currently being used to detect planets around other stars.