U.S. scientists: the aliens may be on earth (Figure).

<P> Keywords: Alien UFO ET alien alien invasion alien pictures </ P> <P> U.S. scientists said, scientists have been trying to search for extraterrestrial life in the universe, but the fact of extraterrestrial life may survive .On Earth, just because they are based on the status of micro-organisms exist, human science and technology can not present their observations only. .</ P> <P align=center> </ P> <P align=center> scientists believe that Mars may have been suitable for life environment. .</ P> <P> extraterrestrial life may exist on the planet </ P> <P> life in the universe, Arizona State University theorist Paul - Davis believes that the earth may still exist in a particular organism formed .areas of life we do not understand. .Davis that the search for extraterrestrial life should be "global mission" to start. .Davis said, "As early as 60 years in the 20th century, when almost no one will believe there is extraterrestrial life, and now claims that the universe is that life is a very popular view. But we still do not know the environment in the class to .the possibility of life automatically appear. for the existence of the earth the mystery of our lives remains unknown, scientists have not systematically explored so far. Many people believe that on Mars, Europa or elsewhere, there is a mysterious life, but nobody ever thought of the Earth .there may be some mysterious life in the end what it was like. "</ P> <P> Davis pointed out that this mysterious life there may be many forms. .Known life on Earth is based on five main elements: carbon, hydrogen, oxygen, nitrogen and phosphorus. .However, the organisms may also be formed by the arsenic, but not phosphorus. .In addition, many elements of life are left spiral shape, while others had the right spiral shape, but the DNA's double helix is always right spiral shape. .Perhaps there is some really left-helical shape with the microbial DNA, but not recognized it. .Davis believes that the hands of scientists due to the current microbiological research techniques are based on common biological methods, so they still can not identify this mysterious life. .If you can identify that will help on Mars or elsewhere in the solar system found a similar life. .</ P> <P> some microbes also carry some genetic information is not based on DNA. .These organisms may exist in extreme environments, such as deep under ground, or in extremely hot spa, or even those living in other organisms. .Davis said, "In the microbial world, some micro-organisms may have a different biochemical methods, and produce the results of the second or concurrent gene. We can imagine a series of experimental environment, the life in which recurrent and perish. .In this case, very likely one or a variety of life forms. Of course, a key question is whether they can continue to survive and generate some of the known forms of life with a completely different life. "</ P> <P .> extraterrestrial life that with the asteroid crashes to Earth </ P> <P> scientists previously artificial meteorites will be equipped with micro-organisms into space to study the origin of life. .This meteorite was later returned to Earth, and in the experiment with the latest results. .Rock survived some biological compounds, indicating that if there really extraterrestrial life will be possible to resist high temperature, radiation and other harsh conditions, with the meteorites reach the Earth. .Researchers said it's likely to have extraterrestrial life on Earth origin. .After the meteorite impact, the lives of interstellar exchange really happened? Researchers will be a great baseball man meteorite, attached to the European Space Agency "FotonM3" unmanned spacecraft's exterior, to test whether biological material in the space between .survive the journey. .Artificial meteorite piece northern Scotland, Orkney Islands, is carved from the rock, containing micro-organisms become fossils and microbial molecular signals. .In the re-entry process, the artificial meteorite completely exposed to the atmosphere. .</ P> <P> The study also showed that the live microorganisms in a higher survival rate of the larger rocks. .If the rock volume to 20 cubic centimeters or greater, 200 degrees C can affect the central rocks, life forms can survive. .Germ theory that the planets in different organisms multiply into a life on the planet, the Earth is also included. .If the germ theory to explain the origin of life on Earth, the scientists involved in the study believed that Mars most likely to be the birthplace of life. .The results show that a meteorite from Mars that 5% successful hit Earth. .It is interesting lives may take them to the earth by the. .</ P>.