Why do astronomers infer that the Sun's energy comes from nuclear fusion reactions...

c. Why do astronomers infer that the Sun's energy comes from nuclear fusion reactions? How do we know it does not come from chemical burning? d. Explain how the Sun produces energy by nuclear fusion. e. When we look at stars in the sky we see a wide range of brightness. Explain the factors that would make one star appear brighter than another. (Please explain in your own words, if possible)

What is Hubble's Law and its significance?

What is Hubble's Law and its significance? Describe the large-scale structure of the universe. (Please reply in your own words, if possible)

Discussion questions - extraterrestrial intelligent civilization

d. Would it be possible to communicate with an extraterrestrial intelligent civilization? k. Compare the solar system with the Milky Way Galaxy. (They are very different, but the terms are often confused.) l. Describe the nature of the material between the stars, and how is it observed. (Please reply in your own words, if possible)

Astronomy: Sun formation, planet detection, galaxy history

n. Evidence is strong that the formation of the Sun (and its family of planets) happened by the same processes as the formation of stars. Explain. o. How are planets detected around other stars? p. Did the Sun and solar system form in the first half or last half of our galaxy's history? Explain.

Extraterrestrial life research

Explain how the science of astronomy is being validated, updated, and perfected by continuous astronomical research and how this is related to speculation about extraterrestrial life