保护地球，探索宇宙，发现文明
2023年6月30日 Orbits of Potentially Hazardous Asteroids Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find ...
由NASA组成的卫星团队一直在分析澳大利亚大火产生的气溶胶和烟雾。 VIIIRS红绿蓝图像提供了烟雾的“真彩”视图。（请注意，这些图像并不代表人类从轨道上看到的图像。在这些图像中，已经去除了会增加“蓝色雾”的瑞利散射效应。）尽管有用，但通常很难分辨云层上的烟雾，有时也很难分辨黑暗的海面上的烟雾。 来源：NASA/ColinSeftor 澳大利亚的大火不仅在当地造成破坏。前所未有的条件，包括灼热和历史干燥，导致形成了异常大量的火积云（pyrCbs）事件。火积云基本上是火灾引起的雷暴。它们是由过热的上升气流引起的灰烬，烟雾和燃烧材料的上升引起的。随着这些物质的冷却，形成了类似于传统雷暴的云，但没有伴随的降水。 火积云事件为烟雾到达高空超过10英里（16公里）的平流层提供了途径。一旦进入平流层，烟雾可从其源头传播数千...
This natural-color image of smoke and fires in several states within Brazil including Amazonas, Mato Grosso, and Rondônia was collected by NOAA/NASA’s Suomi NPP using the VIIRS (Visible Infrared Imaging Radiometer Suite) instrument on August 20, 2019. It is not unusual to see fires in Brazil at this time of year due to high temperatures and low humidit...