Astronomy:Threat from Space
Over the past thousands of years， human beings never realize how vulnerable the earth is. Now the scientists found out that the solar system which creates the earth will also bring disaster to it someday in the future. So they began to divert their attention to the outer space of the earth so as to resist the attacks from those asteroids wandering in the space. In the vast universe， the earth is susceptible to various kinds of attacks. The scientists began to realize that the biggest threat the earth faces is not coming from itself， but from the space. Besides the collisions of asteroids， the microbes of Mars has always been the focus of the scientists. Some people believe that the virus coming from other planets results in the extinction of dinosaurs. This also warns people if the samples from Mars should be brought to the earth.
- Added：2006
- Country：America
- Duration：60
- Time of update：2011/8/17 9:42:06