Only last week the people of our the planet welcomed the Earth Day, but the lessons we learned about Earth due to space, will remain with us for a long time. For billions of years Earth, the only contact with other planets that had life in our world was weak random flashes of light in the night sky. Star-points, planets, cosmic clouds, and the diffuse nebula rare comet — that’s all we saw.
And although all we have seen is very impressive, about our own world it says very little. At least until we look a little deeper. Fortunately, thanks to human ambition, ingenuity, technology and cooperation, we were able to do. And as it turned out, most of the worlds in our Solar system — very ugly, catastrophically incapable of harboring life.
Temperatures on airless mercury can melt the lead in throughout the day, and at night — to freeze carbon dioxide until dry ice.
The situation on Venus is even worse: its atmosphere with a pressure of 90 earth and nowhere vanishing cloud layers of sulfuric acid turned this world into such a stove is that the temperature of the mercury will seem a breeze. Of all Soviet spacecraft which we planted on the surface Venus, the longest lasted “Venera-13” — it worked for 127 minutes before you die.
Mars is also extremely cold and desolate planet. Thin atmosphere and the distance from the Sun causes water on the surface of this the world will always be frozen or in the form of atmospheric steam. Though the conditions for life could be much more promising billions of years ago, the inability of Mars to hold onto its atmosphere has led to the fact that this world — as we now know — have been fruitless and lifeless.
What’s next? Giant worlds of our Solar system consist of huge deposits of hydrogen and helium, and any other complex molecules that there can exist, will be literally buried under these elements — on them will be literally thousands of miles of ocean. Yes, these worlds beautiful, vast, they can be massive and solid core, in many times bigger than our planet, but at the moment there is not a single famous people and other life on earth, the way to settle.
Some satellites orbiting these gas giants, however, can to be more promising, but we won’t know until we visit them. Some of the smaller moons almost no atmosphere, on the other the internal of the moon have the impact of a catastrophic tidal forces, which break the peace and turn the surface to molten lava. And there are a few worlds that can something promise of life if not on the surface, at least underneath.
Titan, Saturn’s giant moon, has the most dense atmosphere among all the known current at the time of the moons, and the atmospheric pressure at Titan’s surface is even higher than on Earth. In addition, it is the only the known world (except ours) with the current stable liquid on surface. Due to lower temperatures and distance from the Sun, and also a small amount of heat, which produces Saturn and the power of the Titan, all the water in this world completely frozen. But the pressure and temperature conditions suitable for the existence of liquid of methane on the surface. And if terrestrial life is unlikely to be able to live in conditions Titanium may titanium can?
In addition to Titanium, there are at least two of the ice world — satellite Jupiter’s Europa and Saturn’s moon Enceladus — which seem to have a lot of water, hidden under a thick layer of ice that it even erupts surface. The icy surface of Europe shows a kind of plate tectonics plates that we have on Earth.
Because these moons, there is liquid water, and thanks tidal heat on the bottom of the ocean, we may be faced with the same conditions life found at deep-sea hydrothermal vents at the bottom the oceans of the Earth.
We can move even further into the Solar system when it comes to explore the vast Universe and what can be possible the origin of life, maybe even earth-like. We not only identified planets around other stars, but also revealed the following:
- solid planets with a mass, size and density comparable to the earth;
- the planet in a potentially habitable zone, i.e. at this distance
from their star that the surface of the planet will be living water;
- planet, the atmosphere which we could measure spektroskopicheskie, and thus to find out the molecular components of their atmospheres.
The overall goal, of course, is to find a planet with all three conditions to find the planet with the biomarkers that will not leave us doubt that it is life. While we only found two, but we can to measure the atmospheres of planets about the size of Neptune. To begin to measure the atmosphere of earth-like planets, we will need new telescopes and new advances in technology.
But why stop at our own galaxy? In the end all, the Hubble space telescope showed us that no matter what we find in our own galaxy, there are literally hundreds billion other galaxies, each with billions of chances the emergence of his own life — another, similar to ours, reasonable and so on.
In 1990-ies we made a bold action — they took the space the Hubble telescope and pointed it to the area of the sky, which was not… nothing. No galaxies, nebulae, stars were not visible even with using the most powerful ground-based telescopes.
We made 342 snapshot of this region: the equivalent of ten days continuous observation. Perhaps, it would be most wasteful the use of the Hubble space telescope, if he hadn’t found anything. Because we have not seen anything. We have sent telescopes and did not find anything. But this time we were lucky. And that’s what saw the Hubble WFPC2 camera.
Yes, we found there five or six faint stars of our milky Way, but outside of it? Thousands of galaxies: about 3,000, to be exact, in this tiny region of space. Since then, we’ve always come back to in this process, looking deeper and deeper, catching every single photon. Because of this, we finally learned — and it is the most conservative estimates — in the observable Universe there are at least 200 billion galaxies.
And yet after all we have learned about other worlds in our The solar system, about possible worlds, like Earth, around other stars and all chances of the emergence of life in the galaxies in the Universe, after we increased the potential for discoveries…
We have only one Earth.
This photo is the famous photo of Earth rising — the first opportunity to see the full disk of the Earth through the eyes of a man. On this occasion, well
voted astronaut bill Anders: “We came all the way to the moon, but our most important discovery was the Earth.”
And every astronaut who leaves Earth and looks down on the world says about the same thing. Astronaut “Apollo 8” Frank Borman said
“When you look from the moon to the Earth, all these differences and ethnic strife fade into the background, and realize that, maybe this world only, and the bitterness, why the hell are we not can live together like normal people”.
Or Michael Collins, astronaut “Apollo 11”:
“Oddly enough, the most profound feeling I experienced looking at the Earth was, my God, this little thing is such fragile here.”
Or astronaut Apollo 9 and 15:
“Truly it is an oasis — and we’re not very good about it care. I think the real contribution to the salvation of the Earth will increase attention to this issue”.
So, as we look to the future, exploring the Universe and increasing our knowledge and understanding of all this, we should not forget about how fragile and precarious our existence is. It took the billions of years that humanity has emerged, and it exists a little less 100 000 years. Can we cut ourselves from this blue world? Yes easily.