视频简介
In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, Horizon reveals the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles...。【内容简介】 东非大裂谷自红海至赞比西河口，连绵三千里，从太空都能看到。这里是多姿多彩的地方，有喷发的火山、覆盖着森林的高山、美丽的峡谷、广袤的草原、巨大的平湖和河流，是鳄鱼、河马、狮子、大象、火烈鸟和非洲人的家园。BBC采用最新的高清摄影技术，探讨了形式东非大裂谷的地质力量，展现世界上野生动物品种最多的地貌。 Visible from space, Africa's Great Rift Valley runs three thousand miles from the Red Sea to the mouth of the Zambezi. It's a diverse terrain of erupting volcanoes, forest-clad mountains, spectacular valleys, rolling grassl...。