AST 248: The Search for Life in the Universe

Keep answers short.

1. Describe the development that freed living systems from its dependence on the limited information storage capacity of DNA.
2. Suppose a 10 km radius asteroid impacts the Earth, is pulverized, and its mass is spread uniformly over the Earth's surface. How thick a layer would be produced?
3. Why are craters produced by impacts from space, even if they impact tangentially, overwhelmingly circular?
4. Approximately how many megatons of TNT would be necessary for an explosion to produce global effects on the environment?
5. If a long lead time was available, what would be the easiest way to deflect a potential impacting object out of Earth's path?
6. Why is a water/carbon chemistry basis for life expected to be universal?
7. Give an example of convergent evolution: name the animals/plants involved and the feature involved.
8. What is the difference in approaches taken by artificial life compared to genetic modification to create the simplest living organisms?