天文学家用NASA的哈勃太空望远镜发现了一个巨大的氢云，从一个叫格利泽436b的星球上蒸发出来的。由于母星的极端辐射，这颗行星的大气层正在蒸发中。 欲了解更多信息，请访问http://science.nasa.gov/。 点击这里查看更多视频：https://alugha.com/NASA
LicenseCreative Commons Attribution
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
