Watching Earth From Space

Watching Earth from Space. Written by David Dreier.

从太空观测地球 作者：大卫·德赖尔

Introduction. The world right around you has hills, trees, homes, and buildings. Standing on the sidewalk, you can only see what is happening on your street. That is your normal view. Imagine looking down at your town or earth from space. You would have a much wider view. From space, you could see and photograph your entire country.

引言 你身边的世界有山丘、树木、住宅和建筑。 站在人行道上，你只能看到自己所在街道上发生的事。 这是你日常能看到的景象。 想象一下从太空俯瞰你的小镇或是整个地球。 你会看到广阔得多的景象。 从太空中，你可以看到并拍下整个国家的画面。

Scientists who study the geography of Earth's surface use cameras on satellites in orbit. The International Space Station is one satellite that has cameras. The space station's orbit is nearly 400 kilometers, 250 miles, above Earth.

研究地球表面地理的科学家会使用轨道卫星上的摄像头。 国际空间站就是一颗配备了摄像头的卫星。 空间站的运行轨道距离地球近400公里，即250英里。

Images made by orbiting cameras track changes that happen to Earth over time. They see the big picture. These images record pollution damage, climate changes, and changes to land surfaces. They also show us the effects of too many people living in an area.

轨道摄像头拍摄的影像可以追踪地球随时间发生的变化。 它们能观测到全局情况。 这些影像记录了污染破坏、气候变化以及地表的变化。 它们也能向我们展示某个区域人口过多带来的影响。

Weather satellites watch storms. Large storms, such as hurricanes, can cause great damage and loss of life. Not all areas have storm warning systems to let people know a dangerous storm is coming in time for them to escape the storm's path. Images from orbiting satellites help scientists predict where a storm will go.

气象卫星会观测风暴。 大型风暴，比如飓风，会造成严重的破坏和人员伤亡。 不是所有地区都有风暴预警系统，能及时告知人们危险风暴即将来临，好让他们避开风暴的移动路线。 轨道卫星拍摄的影像能帮助科学家预测风暴的移动方向。

Keeping watch on pollution. Images from space can show where air or water is being polluted. For example, they can show where oil from an oil spill is spreading. This information can help people who live nearby. It can also help with cleanup efforts. Images can record how long it takes for the environment to recover.

监测污染情况 太空拍摄的影像可以显示空气或水被污染的区域。 比如，它们可以显示漏油事故中的石油正在向哪里扩散。 这些信息可以帮助住在附近的居民。 也能助力清理工作的开展。 影像还能记录环境恢复需要的时长。