Life on Earth has sent a distant solar system

New theory on the movement of space debris increases the likelihood that the stellar systems exchange bioveschestvom.
There was a time when the solar system by rain sprinkled stones. Just look at the surface covered with craters of no atmosphere of planets like Mercury and the moon, to understand the scope of the cross-fire, which occurred when the worlds coming to us just forming, and those cosmic debris that helped to create it, to fly freely in space. Even today, the planets and their satellites are periodically exchanged between the rubble, and it is possible that some stones from Mars, long ago carved into space stray meteorite slowly gyrate, approaching the Earth's orbit.
This interplanetary metabolism has long spawned the theory of panspermia, which states that life on Earth may have arisen not here, and was entered in the form of organic building blocks, or even microorganisms from distant planets. Land, in turn, could also fertilize other worlds. The catch is that the solar system is limited in size, and the Earth, as we know, this is the only place that can preserve and maintain traveling germs of life.
But the situation becomes much more interesting, if we extend the list of candidates for the biological metabolism, to include other solar systems. Such a hypothesis, called the litopanspermiya always seemed very attractive, but not worthy of special attention. Physics of interstellar exchange is so complex that, in practice, no debris to make such a journey can not. At least that was the common belief. But the new paper, published in the journal Astrobiology, the new energy charges litospermii idea because in its opinion concluded that the interstellar exchange of life is much more likely than we thought.
Astrophysicists to the simplest part of panspermia theories litopanspermii and, oddly enough, is the very biology. In the universe is full of water, hydrocarbons, and even amino acids - all of which can carry a free flight space debris. In 2011, geologists announced that crashed in 2000 at the Earth meteorite contained in the structure aminoksiloty and other prebiotic substances. Moreover, they were all at different levels of complexity - and that means that the meteorite in flight "be done to a turn" them, possibly with the help of the remaining water and the heat generated by radioactive substances.
But even if the organic load during such a long trip can survive and even develop - still remains the question of how it is delivered from the sender to the recipient. And here the theory litopanspermii serious problems. Earlier models of interstellar movement based on the idea that the fragments are ejected from the solar system by gravitational encounters with large cosmic bodies such as Jupiter. In this case, they can move at a speed of about 8 kilometers per second, or about 18,000 miles per hour. At that speed, the debris can not get into the gravitational field of another star system, even if it will reach. "It is very unlikely that even a single meteor flying to the planets in our solar system, will fall on the terrestrial planets in another solar system for the entire period of the existence of our solar system," - wrote in 2003 in their research astrophysicist at the University of Arizona H. Jay Melosh (H. Jay Melosh). In this work, he tried once and for all put an end to the theory litopanspermii. If they can not fly away our debris, then other debris likely to fly to us no more.
But this is only if you stick to the old model of scattering debris. A group of researchers from Princeton University, Arizona State University and the Center for Astrobiology Spain has approached this issue with the other hand, has developed a computer model of the slow flight, which is called the "weak movement." According to this model, the debris fly through the solar system outside the spiral, and eventually get to a point as far away from their native sun, you need only a small perturbation in order to push them in the direction of interstellar space. "At such a point, - says Princeton astrophysicist Edward Belbruno (Edward Belbruno), which is one of the authors of scientific papers on this subject - the debris flying out so slowly that it is for their departure is possible to apply the theory of randomness and chaos."
The problem is that at low speeds will need a lot of time to move to the next solar system, and the journey can last half a billion years or more. Many do not survive even the strongest organic materials. But about four and a half billion years ago, when our sun was formed, it was part of a close group of emerging stars, known as the local cluster. They settled down pretty tight and close to each other - and in this case, the flight could be much shorter.
"After 100-200 million years star parted, and the possibility of a weak move sharply reduced - says Belbruno. - But the window is still there. " Analysis of the Earth's species is cause for optimism, because it shows that the terrestrial organic matter could be formed at a very early stage of the solar system, that is, just at a time when there is a window.
In fact, the number of fragments that reach another solar system seems very low - from five to 12 per 10,000. But because the amount of debris, flying away from their systems at a low rate, is trillions annually, neighboring worlds can draw on their orbits a billion such pieces a year. So that we may be among the recipients of such a huge mass of debris flying anywhere. In fact, hardly any of the people currently living with a stranger she met, but now slightly increased the chances that we ourselves can be aliens.