在庆祝哈勃太空望远镜成立 25 周年之际，科学家们在反思宇航员是否可以再使用望远镜做更大的探勘并发挥关键作用。 访问 http://science.nasa.gov/ 了解更多信息。 点击这里查看更多视频：https://alugha.com/NASA 视频于2015年制作
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Visit http://science.nasa.gov/ for more. Earth is surrounded by electrons that can be disruptive to our technology. NASA is using high-altitude balloons and spacecraft to monitor and understand these particles in the radiation belts surrounding our planet. Click here to see more videos: https://al
Explore how astronomers and scientists use astronomical units to measure distances in the solar system in this video adapted from NASA. The astronomical unit (au) -- equal to the average distance from Earth to the Sun -- is a convenient unit of measure when talking about distances in the solar syste
