| 姓名:Gabrielle |  | 188.143.232.** | | 時間:2015/11/2 上午 12:50:12 | | ☆☆☆☆☆ | | Get a job <a href=" http://www.guitart.eu/index.php/the-best-essay-writers.pptx ">the bluest eye research paper</a> Comet 21P/Giacobini-Zinner has an orbital period of 6 years and 4 months around the sun, so the dusty track of cometary debris is renewed on each comet pass. The orbital period of the comet has also helped astro***mers predict the intensity of each meteor shower. In 2011, for example, the comet was at closest approach to the sun (perihelion), which explains the high meteor rates that year. So what about 2013, two years after perihelion? Well, that璽??s anyone璽??s guess.
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