DART vs Dimorphos
2023-03-09
浏览次数: 17
在首次从地球出发的行星防御测试任务中，DART航天器于2022年9月26日拍摄了这张特写，三秒钟后，它撞上了小行星小卫星Dimorphos的表面。在两块巨石之间的预计撞击点，可以描绘出由两块长太阳能电池板组成的航天器轮廓。较大的巨石直径约6.5米。DART（双小行星重定向测试）航天器的质量约为570公斤，而Dimorphos（近地双小行星系统中较小的成员）的估计质量约为50亿公斤。宇宙飞船的直接动能撞击明显地改变了Dimorphos的速度，其速度只改变了不到百分之一，将其绕较大的小行星65803 Didymos运行的12小时周期缩短了约33分钟。除了成功地展示了一种改变小行星轨道的技术，这种技术可以防止未来小行星撞击地球，行星尺度的撞击实验还为150米大小的Dimorphos提供了一个类似彗星的物质尾巴。
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On the first planetary defense test mission from planet Earth, the DART spacecraft captured this close-up on 26 September 2022, three seconds before slamming into the surface of asteroid moonlet Dimorphos. The spacecraft's outline with two long solar panels is traced at its projected point of impact between two boulders. The larger boulder is about 6.5 meters across. While the DART (Double Asteroid Redirection Test) spacecraft had a mass of some 570 kilograms, the estimated mass of Dimorphos, the smaller member of a near-Earth binary asteroid system, was about 5 billion kilograms. The direct kinetic impact of the spacecraft measurably altered the speed of Dimorphos by a fraction of a percent, reducing its 12 hour orbital period around its larger companion asteroid 65803 Didymos by about 33 minutes. Beyond successfully demonstrating a technique to change an asteroid's orbit that can prevent future asteroid strikes on planet Earth, the planetary-scale impact experiment has given the 150-meter-sized Dimorphos a comet-like tail of material.