. Astronomy is the oldest science and some important insights about the universe were gained even before the invention of the telescope. In no more than 750 words, address the following two questions: a. In terms of the scientific method, how does astronomy differ from a lab science like chemistry or biology? How can astronomers be confident of their understanding of objects that are remote from the Earth? b. Ancient cultures built some impressive structures that incorporated astronomical functions and information (Stonehenge, Chichen Itza, the Great Pyramid). A friend or acquaintance of yours tries to argue that some of these structures and artifacts are evidence of “ancient astronauts” or visits by intelligent aliens. How would you rebut or argue against this idea? 2. Astronomers use telescopes to learn about the universe. Since the time of Galileo, optical telescopes have grown in aperture from a centimeter to ten meters, and astronomers have put telescopes in space and have used them to detect electromagnetic radiation at wavelengths not visible to the eye. In no more than 750 words, address the following questions about telescopes: a. What are the advantages of large telescopes? Provide at least one. b. Why do astronomers want telescopes in space when putting them there is expensive? c. What are some examples of wavelength regions beyond the spectrum of visible light where astronomers can learn about the universe? Provide at least two. 3. Just twenty years have passed since the discovery of the first planet beyond the Solar System, and over 5000 exoplanets have been found. The limit on detection has reached Earth-like planets and some are habitable. Studying exoplanets recasts our view of our own Solar System. In no more than 750 words, address the following questions about planets near and far. a. What are the two main, indirect methods for finding exoplanets? b. Why is it so difficult to see exoplanets directly in an image? c. What are some similarities or differences between our Solar System and new, distant planet systems? Provide at least one similarity and/or difference. 4. The understanding of how stars function to create elements and how they live and die is one of the greatest achievements of modern astronomy. The Sun is a typical star but some of the more extreme outcomes of evolution occur for massive stars. In no more than 750 words, address the following questions about star birth and death. a. What is the source or cause of the Sun’s light, and how do all the elements in the periodic table get produced? b. What is the general process by which a large diffuse cloud of gas turns into a star and surrounding planets? c. Name of the two end states of stars much more massive than the Sun and describe their physical properties? 5. The past century has shown that we live in a vast and ancient universe. There are about 100 billion galaxies to the limit of our vision and there seems to be nothing special about the location of the Milky Way on any scale. Observations in cosmology have shown that the universe is 13.8 billion years old. Answer the following three questions about the universe we live in: a. Why do astronomers often say that large telescopes are like time machines, or equivalently, why is distant light old light? b. What is the evidence that the universe began in a hot, dense state 13.8 billion years ago? c. The atoms in our bodies and in all the stars in all 100 galaxies form a small percentage of the contents of the universe. What are the two dominant ingredients of the universe and why are astronomers so unsure of their physical nature?