Methane is a colorless substance, odorless and tasteless,so widespread within the Solar System that it is found in large quantities in the atmosphere of Jupiter and Saturn, forms entire seas and lakes on Titan, and possibly covers the surface of the distant dwarf planet Sedna. On planet Earth, this gas is most often used in industry, for example, for the manufacture of rocket fuel. What else can be interesting for this substance and why do scientists believe that methane can reveal the secret of the origin of life on the planet?
How is methane formed?
Researchers have long noticed methane,standing out from deep-sea vents. But while gas abounds in the atmosphere where it is produced by living things, the source of methane on the seabed was a mystery.
Scientists were able to analyze more than 160 samplesrocks found at the bottom of the oceans. Almost every sample contained traces of methane, which helped researchers prove the fact that the scale of oceanic deposits of organic matter is many times higher than the amount of methane contained in the planet's atmosphere.
But how can methane in such an amount form at the bottom of the ocean?
Despite the fact that methane is considered organicsubstance, scientists distinguish 4 completely different ways of its origin in nature. So, biogenic methane is formed during the chemical transformation of organic matter, abiogenic methane is formed as a result of chemical reactions between any inorganic compounds, bacterial methane appears as a result of the activity of microorganisms, and thermogenic is formed in nature as a result of thermochemical processes.
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In order to solve the mystery of the origin of huge methane reservoirs beneath the ocean, scientists analyzed the rocks found at a depth of many kilometers using Raman spectroscopy.
Raman spectroscopy isThis is a method of studying a substance in which a beam of light scattered through contact with a rock is passed through a sample necessary for study. The rays obtained during the experiment are collected in one common beam and passed through a special filter that separates weak rays from strong ones. It is weak rays that are called Raman rays, which make it possible to judge the structure of a particular substance.
As a result of the experiment, it turned out that in allsamples of deep-sea rocks contained a large number of various minerals and gases, which are formed due to the movement of sea water in a trap of hot olivine (or magma). When olivine hardens, water is transformed into hydrogen and methane as a result of serpentinization.
In other words, huge methane pools on the ocean floor are formed not by living organisms, but as a result of geological processes.
Why is methane a sign of life?
Astronomers highlight 4 markers potentiallyhabitable exoplanet. In addition to the presence of methane in the atmosphere, scientists are also looking for water, carbon dioxide and oxygen. If everything can be more or less clear with water, oxygen and carbon dioxide, then why did scientists need methane?
The fact is that methanogens were the firstliving organisms that developed in the primary broth of the Earth. Using methane compounds for energy, these microscopic organisms made it possible for other inhabitants of the planet to appear and evolve.
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Despite the fact that the presence of all markers is not yetwas found on no open planet, the awareness of the fact that life on Earth was born due to methane, allows researchers to take a fresh look at the question of the possibility of life on other planets.
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