偶看新闻兆驰南昌项目:水从何而来？
来源：百度文库 编辑：偶看新闻 时间：2024/04/29 07:55:04
科学快报：水从何而来？
Credit: NASA/JPL-Caltech/L. Allen (Harvard-Smithsonian CfA)
本图授权：NASA/JPL-加州理工/L.阿伦（哈佛-史密森学会CfA）
Water, water everywhere—but where did it come from? From icy comets to Earth's vast oceans, our solar system is chock full of water, yet so far no one has been able to demonstrate how it formed in the first place. Getting atomic oxygen and molecular hydrogen to combine in the deep, cold vacuum of space is nearly impossible. Scientists think the answer may lie in a dusty interstellar cloud, like the one shown here. A team reports today at a meeting of the Royal Astronomical Society in Glasgow, United Kingdom, that each grain of interstellar dust provides a reactive surface on which wayward hydrogen and oxygen can combine into H2O. Eventually the two elements form an icy coating on the grain, the grains in the cloud condense gravitationally, and presto! Comets, icy moons, and seas galore.
水，处处都有——但它来自何方？
从冰冷的彗星，到地球浩瀚的海洋，我们的太阳系充满了水，但到目前为止，还没人证明它最初是如何形成的。想让氧原子与氢分子在极寒的外太空中结合几乎不可能。科学家们推测答案可能就藏在一团，如我们在这里给大家展示的尘埃密布的星云之中。
就在今天，在英国格拉斯哥的英国皇家天文学会的会议上，一个研究小组报告说，游离的氧和氢可以附着在星云中的每一粒尘埃上发生反应，结合形成水分子，最终在尘埃外围形成一层冰。之后，这些尘埃能依靠相互之间的引力渐渐靠拢、长大，很快地，彗星、冰卫星、海洋就这样形成了。