ASTR 1210 Lecture Notes - Lecture 20: Gas Giant, Great Dark Spot, Thermosphere
Document Summary
Global temperatures vary over time, and have tracked carbon dioxide for last 500,000 years: co2 concentration is highest it has been in at least 500k years. Rapid recent increase in co2 concentration: most of co2 increase has happened in the last 50 years. How did earth"s atmosphere end up so different: temperatures just right for oceans of water, oceans keep most of carbon dioxide out of atmosphere, nitrogen remains in atmosphere, life releases oxygen into atmosphere. Why does earth"s climate stay relatively stable: carbon dioxide cycle acts as a thermostat over long term. How might human activity change our planet: global warming from production of greenhouse gases. Jupiter and saturn: mostly hydrogen and helium gas. Uranus and neptune: mostly hydrogen compounds (water, methane, ammonia) Some h and he gas and rocks. Uranus and neptune and denser than saturn because they have less h/he proportionally. What about jupiter: more dense than saturn.