Does extraterrestrial life exist?

If this question was asked years ago, in the 60s, perhaps more than 70% of the people would have answered that we are alone in the universe. Today, more than 90% of the people think that life exists in other worlds. Although, only half of the people actually think that extraterrestrials visited us in the past, or are currently present around Earth.

 Some decades ago, a person that said that he thinks that there is extraterrestrial life could formerly be qualified as insane. Today we can qualify as insane someone who thinks the opposite, that life elsewhere in the universe does not exist. It is like somebody living in an apartment in the middle of New York, and he closes all his Windows curtains, and he says that he is the only one inhabitant of the big city or the world.

Scientists qualified as a miracle the fact that life on Earth developed. They have said that we are, on Earth, at an ideal distance from the Sun where the temperature is adequate to contain life forms. And places, like for example Venus, with enormous atmospheric pressures on its surface, acids in its clouds, and temperatures exceeding 400 degrees Celsius, were considered as impossible sites where we could find life as we know on Earth.

Also in the past, there was no certainty about whether many of the stars that we see in the night sky could have planets. We did not know about the existence of extra Solar System planets.

Today all of that has changed. We know that we live around an average star, out of 400 billion that exist in our galaxy, the Milky Way. And it is estimated that the known universe there are close to a trillion galaxies. And some scientists now consider the possibility of the existence of several universes parallel to ours. Then, someone is still thinking that we are alone in this infinite Universe?

Currently it is also known that life can also develop in extreme conditions. On the bottoms of oceans, in the mid-oceanic ridges, we have found life in the form of bacteria, plants, and large animals. And we are talking about life in extreme conditions, where the temperature is higher than 400 degrees Celsius, under high pressures, with no sunlight, and the presence of corrosive acids. The amount of live mass of all living beings in the mid-oceanic ridges, at the bottom of the oceans, is superior to the biomass of all the insects that exist on the surface of the Earth. We are talking about a different live form, which seems to develop in extreme conditions, living in our oceans at high depths, which it is not an isolated and small group. So it seems logical to think on the possibility that there might be living beings, as bacteria on the surface of Venus, which seems to be an extreme environment.

Additionally, it has been discovered that bacteria can live inside the rocks, sometimes thousands of meters deep. And scientists are considering that bacteria could live within meteorites or comets that might be populating of life countless planets while they travel.

The Kepler space telescope and other modern telescopes on the Earth's surface, have found several planets orbiting around stars, some of them in similar conditions to the Earth. We did not have before the certainty about other planets outside the Solar system, but every day new planets are discovered out there.

Then, we already know that it is not necessary to ask ourselves if there is life out there. We now know, for sure, that the Universe is a populated place, with many different life forms. Perhaps the Universe itself is an enormous living organism.

The other question that many people ask themselves is if there are intelligent beings from other planets that came to Earth in the past, or if they are currently watching us, closely and silently. Even today, many people react negatively to this statement, by saying that it is impossible, since the distances between the stars is so long, that even traveling close to the speed of light, it would take too much time to them to arrive to our planet. It is not possible to travel at a speed greater than that of light. Some people even criticize others who think that this is possible.

Perhaps Einstein was right and it is not likely to travel faster than the speed of light and this would be the proof that it is impossible that beings from other planets arrive to Earth, even if they exist. But... is there another way to travel?

Let us imagine that we are aboriginal people who live in a faraway island. At the distant horizon we can see other islands. As nobody has visited us in our island, we think that we are the only living beings in the universe; our “universe” consists of Islands and the large ocean that we know. Now, some of our local scientists may say that the distances between the Islands are too large and someone swimming would never reach another island. Therefore, if there is life out there, in another island, it is impossible that they arrive to our place, because they could not cross great distances. This is based on what our scientist has said and that is absolutely true: "it is impossible to swim from one island to another one". This is a law that cannot be violated. Whoever tries it, he will die.

But, what if there are other people living out there, on the distant Islands? And what if they have developed technology and they can arrive in speedboats or crossing the sky in airplanes? Perhaps they can violate the established law that it is impossible to go from one island to the other? How would we react to this possibility, which someone else come to us on board of unknown ships that appear to violate the laws that we know?

Extraterrestrial life exists, that's for sure. Some of them may be more intelligent than us, and they could be using technology that we believe violates laws that we know. Perhaps they have learned how to move from one location to another one in the space-time, instantly, and it seems to us that it violates the laws of Einstein. Perhaps we do not know yet other laws that are above the law already known by our scientists.

Talking about the possibility that extraterrestrial life exists or not, or if they have have been on Earth in the past is a personal belief. Everyone believes what his personal experiences have taught him. It would be rude to make fun of someone who does not believe that there is extraterrestrial life, as his beliefs and experiences tell him that. Everyone is free to believe it or not. What is very clear is that the future, for sure, will be giving us the answers to these questions.