Humanity has three chances to find aliens
Ever since the first people sent their views to the sky, the planets, stars and galaxies outside of our home world, our imagination filled the opportunity to find extraterrestrial life. However, when we are approaching this issue from a scientific point of view, we still do not have the first convincing evidence of life beyond Earth. Complex, diverse life forms that we see on Earth are the result of more than four billion years of evolution, but in space there are ingredients for life all the time. We began to find organic molecules throughout our solar system, interstellar space and even other stars. How long will it be before we get the confirmation of the existence of something living beyond Earth? Today we are searching using the four basic methods. Which of them will pay off first - that nobody knows.
to display the life, we need fundamental ingredients necessary for life processes: raw materials from the periodic table. To do this, you need to live and died several generations of stars overtake their nuclear fuel. We found a star with planets hard at hand, that seven billion years older than the Earth and have all the necessary elements for life. We found Earth-like planets in the habitable zones of potentially that of other stars in the galaxy. We found organic molecules of sugars and amino acids to ethyl formate, which gives her a raspberry smell everywhere, from asteroids to stars and young protoplanetary disks and molecular gas clouds.
In general, we believe that in our Milky Way galaxy have over a trillion (10 12) of the planets, and hence the chances of life. But between the planets with the ingredients and genuine, nice alien life there is a huge difference. We do not know whether there are in the universe some other examples of life, apart from those that we have seen in the world. Although scientists strongly suspect that if the whole universe will have the same ingredients and identical laws of nature, the uniqueness of life on Earth is extremely unlikely, we have no right to make such a conclusion is unfounded. In fact, we do not even know the answer to the question, as we have moved from a non-living to the living? Our existence is proof that this is possible. We can assume that if life will be somewhere in the universe, it can achieve three different levels:
- The life begins on a planet, but it can not exist, flourish and change the
- Life is thriving, kept and preserved for billions of years, making significant changes to the surface properties of the world, which lives
- Life is reasonable, technologically advanced, and any attempts to communicate with the cosmos, or conquer it, or both
Obviously, more advanced features more of us delight and excite the mind, but they are less likely to occur. However, sometimes the rarest things easier to find, because they will stand out from the rest. Here are a few different methods that we can use to search for a variety of life forms. Three chance for humanity to find life beyond Earth.
Search in the solar system
Although life thrives on Earth billions of years, other worlds, it seems, have no such splendor. If these are life, she probably hangs in the primitive state. Mars and Venus was wet and warm past, like the Earth, but Mars today is cold and barren, and Venus is poisonous and hot. Meteorites that fall to Earth, contain not only the amino acids necessary for life processes, but also many other elements that are not associated with biological processes on Earth. Moon like Europe and Enceladus possess subsurface oceans with liquid water, which may be hydrothermal vents. At the bottom of Earth's oceans, they are usually associated with life.
Although we have not found evidence of the existence of living beings, past or present, in another world, the possibility of such an indescribably exciting. On Mars, there are sedimentary rocks formed by water last; Can we find fossils, when they dare to dig? On Europe and Enceladus may be the entire ocean, open for research; Do we find microbes or something better in their waters? There is even speculation that diatoms, examples of primitive life forms that are found in fragments of meteorites, may have an extraterrestrial origin. This is the least developed form of life of all that we can imagine, but we get a lot of worlds that we can physically get to visit, to measure. If primitive, simple life is everywhere, careful study of our solar system will reveal it.
Search for other exoplanets
Over the past 25 years, the area Sciences ekzoplanetarnyh gave scientists a treasure trove of precious discovery, thousands of planets in orbit other stars. Many of these worlds are small, hard and are on the right distance from their star which allows admit that they have atmospheres and liquid water on the surface. We can not find certain microbes or fossils on them directly, because they are outside the solar system, but there are indirect methods that we might use to search for life, which managed to survive and thrive: search for changes that makes life in the atmosphere of his planet.
Land - the only known planet with such a ratio of molecular oxygen: 21% of our atmosphere - About this 2. Why did it happen? Life has had billions of years to saturate the atmosphere of his biological waste. We think that oxygen is necessary for life, but in fact it is the animals have evolved to use this ingredient to find a use for it. With the improvement of our technology, we can measure the molecular signatures ekzoplanetarnyh atmospheres and possibly even directly visualize exoplanet in search of clouds, oceans, seasons and continental greenery. We have every reason to believe that a stable life on another planet, if we are right to look for it, we seem to be already in this century.
Search intelligent aliens signals
Here on Earth, we had a single-celled life for billions of years, and then evolved multicellular organisms. It took 500 million years since the Cambrian explosion, to complex, multicellular, well-differentiated life has become reasonable, technologically advanced civilization. People have already started to send signals to the stars and has already reached the point where these signals were to reach the nearest stars. Search for extraterrestrial life in an attempt to contact her is risky, but at the same time effective method of finding the aliens.
In the 1960s, we have assumed that the aliens are trying to communicate using radio waves. It took 50 years, and we are not so sure. What kinds of alien signals can exist in nature? How do we decipher them? How will they transmit or receive signals interstellar? Will they conquer the space? Will overcome the huge distances? Everything is possible. If the signal - or, better yet, a spaceship - fly to Earth, our understanding of the universe changed completely, as well as our place in this universe.
Although at the moment this is only a hypothesis, the scientists suggest that life in the universe is likely to spread, and ingredients, and possibilities for its occurrence are found practically everywhere. Life that thrives and sustains itself on the planet, as well as changing atmospheric composition would be less likely. Complex multicellular life is even more rare. And the birth of a technologically advanced, intelligent civilization is so incredible phenomenon that the second chance she will not. However, whatever the odds, we will continue to look for. Options we still have a little bit. And no matter what method will fire the first opening day of another life will be the greatest day in the history of life on Earth.