1. How does the Earth's atmosphere hinder astronomical observations and what methods do astronomers use to eliminate or minimize these problems?
2. Why are reflecting telescopes used in preference to refracting telescopes at major observatories today?
3. In order to measure the radial velocity of a star (the speed of motion towards or away from us) what type of instrument would be used and how would the data be used to derive the velocity?
4. What is meant by the "RNA world"?