英语论文网

st a weather balloon .After this declaration,reports about this UFO events  were gone .This is the most famous UFO events-- Roseville events. Michelle grew in Roseville. And now ,he is a UFO lover .He is very interested in Roseville events. He believed that in 1947,a UFO landed at Roseville.But it was rejected by American military .What’s more,native people all kept in silence under the requirement of the military. Michelle said that he collected some evidence from native people and a solider who didn’t want to publicize his name also agreed to provide more information related. But when Michelle wanted to know the deeper research work done by the military ,he was refused .And now this solider won’t admit this event. Michelle insists that according to statistics l’ve got,Aliens all have a higher intelligence.Human technology obviously can’t make a comparision with them.Those Aliens are friendly ,or we won’t live peacefully now. lt seems that they are seeing about earth .However ,native astronaut department of America denies this .They admitted that Michelle is a great American ,but to this question ,we have an obvious branching.

 

 After above introduction ,you may eager to know whether extraterrestrial intelligence exists or not .Certainly , no one can give the exact answer .But l’d like to explore the possibilities that outer space life may exist.

As we all know that there are millions of stars in the universe ,and life on these planets are experiencing borning. At last ,it will appear what we’ve called scientifical life.

Secondly,scientists have found that water exists in the solar system and under the surface of Mars,there maybe exist liquid water ocean.The satelites of Jupiter---Ganymede and Callisto also have liquid ocean. On top of this ,Enceladus is also filled with water. Even in the atmosphere of Venus ,water exists.Thirdly,scientists’ foot prints have almost touched every part of Earth .They have found that many lives can exist in extremely difficult environment .Such as in the cold and dark ocean , in hot volcanoes and deserts, under the freezing cold ice in south pole. It gives us reminder that life may also exist in other difficult environment on other planets. For example , The Apollo No.12 cosmos airship took back the camera left on the Moon ,to our surprise ,under the camera ,some bacterium coming from earth were still alive .They have been on the Moon for 2 and a half years.At last l want to give an extension of the form of life .Traditionally ,life on Earth is made up of protein and nucleic acid。C  is the basic element .As we all know that  Si  has some similarities with C .   So if Si can create life ,this kind of life doesn’t need organic,absorbing light is enough .What’s more , S also has some similarities with oxygen .Does it mean that in some hotter stars ,life can use S rather than oxygen to breathe ? On top of this , ammonia is similar to water ,so in some huge gas planets ,there may be exist ocean whose component is ammonia, and life may be exist there.

   A famous chemist  West.Mo Fu put forward six kinds of life form.They are as follows ：
one．silicone fluoride life，media ：silicone fluoride
two．fluorinated sulfur life，media ：S
third．nucleic acid and protein life，media：water
four．nucleic acid and protein life，media：nitrogen
five. lipid compounds life， media：methane
six. lipid compounds life，media：hydroge本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。