My First Post about Newly Learned Knowledge through TOEFL
Today’s listening lecture is about one of Saturn’s moons, Titan. Atmosphere on Earth has gone through a process similar to species’ evolution, from an oxygen-lacking atmosphere to an oxygen-abounding atmosphere. And one similar thing between Earth and Titan is that they both have thick atmosphere, and thick atmosphere is one of the key elements in life’s origin. From the background knowledge of physics I learned, to be specific, the Maxwell distribution law of molecular speeds, the greater an celestial object is, the harder for gas molecules to escape from the atmosphere. Titan is the largest moon of Saturn, so it is still possible for it to have a thick atmosphere. It is hard to believe that Earth and Titan will share similarities because their distance to the sun differs so much that light reaching Titan is only one percent of that reaching Earth. Therefore, there are liquid cycles on both objects, though, one is liquid water and the other is liquid methane.
Another similarity is that they both have volcanoes which emit water, methane and ammonia. In the early stages of Earth’s atmosphere, it abounded with carbon dioxide, methane and ammonia. And it might be familiar to many people that key compounds in organic bodies involve amino acids, which need Nitrogen elements. To realize that there was a time, Earth could provide large amounts of ammonia which could form life later is magical. Scientists nowadays are interested in researching the evolution of Titan’s atmosphere, which may shed some light on how life on earth emerged and evolved to the present.
