The two closest to the Earth planet - Mars and Venus - once had vast oceans, extending over many millions of square kilometers. But all the planets with liquid water on the surface is very fragile. Venus could not keep their oceans, and they vanished into space. Recently we learned that Mars lost most of their water, then it turned into a dry and cold desert.
And you, the Earth? What about you? I do not like: what about us ? What is the future in store for the most valuable resource of our planet? Can we squander irreplaceable reserves of water and turn the Earth into a desert-like Venus or Mars?
If the greenhouse effect is a little raise the planet's temperature, the water can start to evaporate into space.
The water at the molecular level
The substance, which we call water consists of two hydrogen atoms and one oxygen atom. The core consists of a hydrogen atom from a single positively charged proton, and rotates around a negatively charged electron. Nevertheless, in the core may also contain one uncharged neutron. Even with this neutron nuclear charge remains positive, but there is one important difference: the atom with a neutron in the nucleus is much heavier than normal hydrogen.
Chemists call this "heavy" hydrogen by deuterium. All chemical reactions deuterium behaves just like a normal hydrogen; he's just harder. If a water molecule hydrogen atoms replaced with deuterium, it will remain the same taste,
the same will be watered flowers - the only difference is that it will become
And the thing is this additional weight: gravity pulls deuterium stronger than normal hydrogen. When hydrogen and deuterium in the atmosphere of our planet, hydrogen rises much higher. And if the planet's gravity is not strong enough - as, for example, Venus, Earth and Mars - ordinary hydrogen can rise so high that it will not return back and leave the planet. Deuterium is also withheld the gravity of the planet.
The initial ratio of hydrogen to deuterium
«Galileo" measured ratio of deuterium to hydrogen in the atmosphere of
Jupiter. The measurement results indicate a ratio of 40,000 to one. Jupiter - a
planet so massive that it can not leave any hydrogen or deuterium. So planetary
scientists, believe that all the planets of the solar system were formed with
the ratio of hydrogen to deuterium.
The actual ratio
If you zacherpn?te a glass of water from any ocean of the Earth, of any lake on every continent, from alpine glaciers or Yellowstone geyser, the ratio of deuterium to hydrogen atoms in it would be 6,250 to one. Not 40,000 to one.
Why is that? Once upon a time, our planet contained a huge amount of hydrogen. Gradually hydrogens left Earth, lowering the ratio from the original 40 000 to 1 to 6250 to 1. Thus, so far the Earth already lost 80% of its hydrogen and the planet since hydrogen contained mostly water loss hydrogen equivalent water loss .
Space Station, NASA Pioneer in 1978 launched a probe into the atmosphere of Venus, which measured its physical and chemical properties. One of the most surprising discoveries was the ratio of hydrogen atoms to deuterium - only 62 to one hundred times lower than in the world.
What follows from this conclusion? Venus was once wet planet, but then turned into a dry desert. As we know, the temperature on the surface of Venus - more than 460 degrees Celsius. Once there were oceans on Venus, but they are boiled away, and ultraviolet sunlight split the water molecules into atoms of oxygen and hydrogen. As a result, light hydrogen atoms have risen too high and the "flowed" in space, while the heavy deuterium remains in the atmosphere. The ratio of hydrogen to deuterium on Venus - evidence of what happened to our neighbor of billions of years ago.
As for Mars rover received NASA «Kyuriositi" data indicate that the ratio of deuterium to hydrogen on this planet seven times less than on Earth. This tells us that Mars and Venus are both in the past has lost almost all of its water.
The total volume of water on Mars (in the icy polar caps, in the atmosphere, the ice layers beneath the surface of the planet) would cover the entire planet ocean depth of 21 meters. Measurements of the ratio of hydrogen-deuterium tell us that early Mars was seven times more water - enough for ocean depth of 137 meters.
Venus and Mars. Planetary scientists know that once upon a time these two planets were wet - just like Earth. None of them could not hold their water long enough for life. Their lesson is simple: water worlds are very fragile. Water worlds that can survive the devastating events, whether natural or caused by their inhabitants - are very rare and therefore priceless.
If we allow the temperature of the planet to rise a couple of degrees above, we can go through this little ecological disaster. But who knows whether they will not be a few degrees the last straw that will launch the same deadly process that once deprived of water Venus and Mars?