Astronomy 2021A/B Lecture Notes - Lecture 7: Chemical Polarity, Voyager 2, Gravity Assist
28 Feb 2016
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Document Summary
Elements: 96% of the mass of living oransims are o,c,h,n but that stuff will be everywhere (o is third most abundant element in the universe, c is the 4th, n is the 6th) Only 2% y mass of our solar system. Only 0. 1% by mass of very old star systems: the process that brought that tiny bit of stuff together (condensation, accretion) should happen around every star. Energy sources: sunlight, consuming others, chemical reactions w inorganics. Energy available from sunlight decreases with the square of the distance from the sun: at 2x earth"s distance, a leaf would get the energy, hard to survive on such small amounts of energy, but possible. Water is key for cellular life: it dissolves organic molecules, allowing their use in cells, it helps transport those molecules in and out of cells, it is involved in many metabolic reactions in cells.
