美国航天局的空间探测器欧西里斯号运行在小行星贝努的轨道上，绘制地图和取样，并在7年后返回地球。 欧西里斯号网站：http://www.asteroidmission.org/ 更多信息请访问http://science.nasa.gov/。 点击这里查看更多视频：https://alugha.com/NASA
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
