As they race to help evacuees from the World Trade Center, the NYPD ESU barely make it out of the North Tower before it collapses.
(02:59)A flying lizard is pursued by a flying snake.
(01:27)Whenever dust storms are observed on Mars, dust devils are often present, leaving long, dark telltale trails.
(03:02)After the zebra's seemingly mysterious journey lies a gigantic source of needed minerals - the Salt Pans.
(01:45)One group of explorers comes downhill only to find their journey just got tougher.
(01:14)The beauty of Central Island in Lake Turkana is explored.
(01:29)In their most ambitious investment, the toymakers faced challenges to create ‘Lego Universe’, an online game for kids...
(02:39)The trip on the Yukon nears an end, and the teams gear up for the last leg - the rapids.
(01:48)What soldiers don't write home about. These guys put on a brave face when calling home. Everything is fine.
(03:02)The brief flyby of Voyagers 1 and 2 raised many questions for spacecraft Galileo to answer.
(03:09)Marty and Willi try and hunt some meat for the group, but can Willi’s gun shoot true?
(02:18)Mercury's surface has remained undisturbed since the dawn of the Solar System, giving us clues to the past.
(03:17)Marty and Matt are trapped on the wrong side of the river and time runs short to get to the LZ.
(01:07)In order to deter German bombers during WWI, Parisians constructed an elaborate fake city several miles away.
(02:47)Meet a Columbian cocaine farmer, for whom growing any other crop would condemn him and his family to poverty.
(02:59)The Seavey brothers push their way through bear country brush on the way to the LZ.
(01:52)Can a Formula One race be run using only electric cars?
(02:53)Millions of golden jellyfish live in just one lake -- and they follow the path of the sun.
(02:40)Willi and the Seavey Brothers come to a crevasse that will test their will.
(02:13)Could you tell a Venetian from a tourist? Students in Venice are tallying the foot traffic in order to help preserve the city.
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