AST 111 Chapter Notes - Chapter 19: Too Cool, Exoplanet, Late Heavy Bombardment

• School: Tunxis Community College
• Department: Astronomy
• Course: AST 111
• Professor: Reynolds

Document Summary

Scientific search for line in the universe now has its own name astrobiology. Focuses on one of the 3 areas: To understand the origin and evolution of like on earth. Searching for worlds that might have conditions suitable for life. Searching for evidence of actual life on other worlds. Learn about the history of life through fossils of organisms that lived and died long ago. Most fall to the bottom of the sea. Radiometric dating confirms these ages and gives us fairly precise ages for fossils. Fossils become increasingly difficult to find as we look deeper into earth"s history for 3 main regions. All life prior to a few hundred years ago was microscopic. Fossil evidence suggest that life on earth was already striving 3. 5 billion years ago. Stromatolites: strikingly small similar to sections of formations known as living stromatolites. Ancient stromatolites are fossils of ancient microbes. Earth had oceans about 4. 3 billion years ago.