The reason why Mars’ atmosphere is very dry and cold is the very little quantity of carbon dioxide. Recently, scientists discovered where Mars’ carbon went and are presenting us with an explanation.
Why did Mars’ carbon disappear
It is believed that Mars’ atmosphere was not always this cold and dry, but actually more welcoming, warmer and wetter. However, in time, this original atmosphere has been stripped away by solar winds until it turned the planet into an arid one. The influence of the solar winds upon the planet’s atmosphere is still active, tons of carbon dioxide leaving the planet every day.
Scientists say that 3.8 billion years ago Mars probably had pretty much the same atmosphere as the Earth. However, the carbon dioxide gradually incorporated into rocks as carbonate or was lost in the air, bringing the red planets’ atmosphere to its current state.
Scientists are still studying the matter
Nonetheless, researchers think that there might be more to it than meets the eye and are decided to look further into the problem by making carbon isotopic measurements at different points in time to learn exactly what happened to the planets’ atmosphere in the past. They will measure the ratio between two stable isotopes of carbon, carbon-12 and carbon-13 which have the same number of protons but different number of neutrons. Neutrons determine the mass of the carbon which means two isotopes of carbon will have different masses.
To measure the isotopic ratio and make a comparison between the ancient and modern one, scientists started looking at the ratio in the meteorites which contain gases that are released by volcanoes from deep inside the planet.
Another way carbon might have fled Mars is called “Sputtering”. This happens when solar winds interact with a planets upper atmosphere. On Mars, Sputtering seems to strip away more or less 100 grams of particles every second. Moreover, ultraviolet photodissociation can change carbon isotopic ratio in a long term process.
All in all, the UV photodissociation process made scientists understand that it will actually be easy for them to detect the amounts of carbonate, measure loss processes and find out how Mars’ atmosphere evolved in time.
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