Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dustcloud that enveloped the planet after the impact.
Faced with any situation that can't be solved by the sheer force of activity, they generate a dustcloud of impatience.
面对任何单凭行动的力量无法解决的情况，他们会产生不耐烦的情绪。
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Though they are strikingly visible in this image from Spitzer's infrared array camera, they are completely obscured in visible light, buried within the core of the surrounding dustcloud.