Since then, as people have directed their views in the sky, to the stars and planets, to other galaxies, their imagination filled the opportunity to find extraterrestrial life. However, years have passed and the search has not been crowned with success.
We are so eager to find life with other stars, then completely forgot about their solar system. Perhaps, it is worth paying attention to the nearest neighbors and look for life there?
When we approach this issue from a scientific point of view we do not have the first convincing confirmation life outside the Earth.[wp_ad_camp_3]
Complex, diverse forms of life that we have seen on Earth, are the result of more than four billions of years of evolution, but in space, ingredients for life there is often.
Astrobiologists suggest looking for signs of life on the planets nearest to the Earth and their satellites.
Ecological niches, suitable for the habitat of microorganisms, there are on Venus and Mars, as well as Enceladus, a satellite Saturn. Let’s include imagination and imagination, apply science and see – what forms of life can be Next to us?
The sister of our Earth is Venus. Space at an altitude of 51-65 kilometers from the surface of Venus may well be inhabited.
Scientists have determined that the temperature there fluctuates from minus 20 to plus 65 degrees Celsius.
The atmosphere consists of water vapor, highly saturated an aerosol of sulfuric acid. Under such conditions, extremophile bacteria survive, feeding on sulfur. For example, the Archaea Pikrofilus, which inhabits hot brines the island of Hokkaido. On Earth, extremophiles occupy the most lifeless places- hot underground sources, oxygen-free reservoirs, permafrost. Some microbes have adapted to eat inorganic substances, assimilating them with the help of solar energy.
Cyanobacteria survive at temperatures up to 70 degrees- at higher values, chlorophyll breaks down in their cells.
A weak magnetic field does not protect Venus from flow high-energy particles of galactic radiation. Solar flares are more dangerous there than on Earth, whose orbit is located further. But the atmosphere of the “planet of the crimson clouds” times denser terrestrial and better delays radiation. However, the chances of surviving on the surface of Venus are all no, scientists believe.
It is unlikely that life has survived beneath the surface planet, in the ground.
The only place where it can be fired is among the clouds high in the atmosphere. Say, the bacterium Deinococcus survives even when irradiated in ten kilograms (this is the unit of the absorbed dose of ionizing radiation). Still there is a hyperthermophilic archaea Thermococcus gammatolerans,it reproduces at 88 degrees and withstands dose of irradiation in three kilograms.
It turns out, on Venus can well be and calmly imagine yourself to live some form of life, but what about Mars?
Many scientists believe that on Mars, three to four a billion years ago splashing oceans of water.
Now, this is evidenced by the contact zones of land and sea around the Northern Wasteland – a vast lowland in the region of the North Pole of the planet. Judging by the preserved relief, the Martian ocean was periodically replenished by moisture swampy lowland.
According to estimates, a third of the water has evaporated, a third has to go neon the formation of the polar ice cap, and another third could be preserved as an ice layer below the surface. Unlike Earth, the climate of early Mars was cold. However, the Red Planet could be the cradle of life. Drying of oceans and lakes does not mean the disappearance life.
It is known that some of its forms are able to extract moisture from the atmosphere or soil.
In addition, on Mars five million years ago there were conditions suitable for life. Then the inclination of the orbit of the planet was 45 degrees – this means that the poles received twice as much solar heat than now.
About the same as the polar regions of the Earth. the polar caps of Mars now do not melt, but five million years ago they resembled present Antarctica. The closest analog of the south pole of Mars is dry frozen breeds of high-mountainous University valley in the south of the continent.
In the front of this valley, which does not melt even in the summer, found microorganisms.
Scientists have isolated parts of the DNA of several strains of bacteria, archaea, and lower mushrooms. Some died, while others were at rest, and in the laboratory, several of these species were able to awaken to life.
On the orbit of Saturn, too, are the oceans. Enceladus. This sixth satellite of the Stourne is covered with ice 40 kilometers. In 2011, the device Cassini fixed at the south pole Enceladus ejection of water, sodium chloride, ammonia and dioxide carbon. This led scientists to assume that under the ice hides the salty ocean. Hence, the satellite has internal sources heat.
According to calculations, the water temperature in the ocean can be26 degrees Celsius, although on the surface .