标签：毁灭地球 相关文章
A male polar bear is searching for a mate. Willing females are few and far between. And the sea ice some of which he travels will soon melt and vanished. He's running out of time to find the mate in this frost frozen desert. Ten miles ahead, a single
自然百科2011年
Few have witnessed this moment, for the male, his only tender encounter in an otherwise solitary life. But it doesn't last long. A rival suitor has also caught the female's scent. Courtship has to be put on hold. He must fight for his rights. He sees
自然百科2012年
For those who can get here in summer, these waters provide a feast of epic proportions. But the good times will be very short, a problem that faces all life in the Polar Regions. Journeying the south across the Arctic Ocean, the first land you/ reach
自然百科2012年
The bison/ form a defensive circle around their young, horns pointing outwards. The wolves need the bison to break rank, but the tables are turning and now the wolves have to retreat. The pack focus their attention on the rear of the herd and the bis
自然百科2012年
As the warm, humid air from the south meets the cold Antarctica, the moisture recurrence crystallizes and snow flakes form from this kind. Each crystal forms around a particle of dust. All have a six folds in the shape, but no two have ever been foun
自然百科2012年
And fishing can be dangerous. A southern sea lion. It uses the speed of a breaking wave to catch up with the gentoos. Sea lions normally eat fish. So he is used to catching streamline swimmers. But the gentoos seem more than his match-up at sea. He m
自然百科2012年
Radiation causes damage at the most fundamental level. It mutates the blueprint of life, DNA. Earth's magnetosphere is our crucial defense. It's so fundamental to our evolution and continued existence that the race is on to understand why it's changi
自然百科2011年
Earth's magnetic field has reversed thousands of times since its formation 4.5 billion years ago. And scientists now believe that the next reversal is imminent. The race is on to predicting exactly when it will occur. In 2010, the European Space Agen
自然百科2011年
Glatsmire's model shows that the magnetic poles swap places spontaneously due to / complex processes within the core. We were used to the idea that a compass points somewhere near the North Pole and hence we can use it for navigation, but there are p
自然百科2011年
By analyzing different samples of lava, Herrero / Bervera has built up a picture of how the filed has changed since long before humans were around. They are actually the recorders of the Earth's magnetic field in hundreds of years, thousands of years
自然百科2011年
It's clear from the fact that the Martian crust is strongly magnetized, that there must have been a magnetic field on Mars in the past, that the only way we know to magnetize rocks is for them to form in the presence of magnetic field. Why did Mars l
自然百科2011年
The loss of the magnetic field has a catastrophic impact on the planet's evolution. Mars becomes the red planet we see today. If earths magnetic protection continues to fade, would it suffer the same fate? If it vanishes completely, the planet might
自然百科2011年
Blockson's computer model reveals that at the South Atlantic Anomaly, the magnetic field isn't just weaker than anywhere else on the planet. It's actually reversed polarity. There is a patch on the core in the South Atlantic where things are not poin
自然百科2011年
The randoms of the sea ice are occupied by sun- bathing seals that have been here all winter. But the new arrivals're following the retreating ice edge and they have come here to hunt. Killer whales, the oceans' top predator. Killers are like wolves,
自然百科2012年
Exhausted, it no longer has the energy to pull itself to safety. And the killers are moving in. Game over. Although such team hunts are rarely seen, scientists believe they may be the most complex ever documented in the natural world. They were first
自然百科2012年
The seal is now what the killer wanted, but the hunt is far from over. They need to wrap their prey by the tail while avoiding its snapping jaws. Only them will they be able to pull it down and drown it. Side swipes create farther underwater turbulen
自然百科2012年
Brazil and China have failed in their mission to launch a climate-monitoring satellite into orbit on Monday. The China-Brazil Earth Resources Satellite 3, or CBERS-3 was destroyed after a Chinese Long March 4B rocket launched from northern Chinas Tai
CCTV9英语新闻2013年12月
These ice blocks are the size of sky creepers, and this is the bill of more glance with scoten seize man somehow travel on foot. It is one hundred miles long and one of the largest species on earth. Not nothing could prepare those early ex-dollars fo
自然百科2012年
Serious produce server Neser Balwich directs from the front seat while aerial cameraman Mike Calen controls the camera attached to the lows. Above 10,000 feet, the pilot must breathe oxygen through a passed tool beneath the nostrils. Approaching the
自然百科2012年
End of the run. No! Ive got him coming out, I just didnt get him going back in. All right! Below the sea ice, the dive team is setting up an underwater studio. Using a rang of waterproof lights and time-lapse cameras, they hope to capture the growth
自然百科2012年