A class of chemicals, oxides of manganese, which were detected at high levels in rocks of Mars by the scientific bodies of the rover Curiosity of NASA, show that once the neighboring planet had more oxygen in the atmosphere than today.
The researchers, led by planetary scientist Nina Lanza National Laboratory Los Alamos in New Mexico, made a notice published in the journal “Geophysical Research Letters” of the American Geophysical Union.
The increased oxygen on Mars is associated rather with the time when the planet had abundant water. Indications for more oxygen, in conjunction with other findings of the same American robotic rovers, such as the existence of ancient lakes indicate that the “Red Planet” looked more like the Earth billions of years ago.
“Now that we have discovered these oxides to Mars, we wonder how on earth can be created. The only ways to Earth that we know how to produce these manganese oxides, is involved either atmospheric oxonium, or germs, “the Lanza said.
Because, for the moment at least, the possibility of microbes seem far-fetched, scientists thought most likely that the answer lies in being much more oxygen in the Martian atmosphere. “The oxides of manganese can not be created without plenty of water in liquid form and without strongly oxidizing conditions. Here on Earth we had plenty of water and manganese oxides were not created only when oxygen levels in Earth’s atmosphere rose”, the Lanza said.
For geoscientists, the study of manganese oxide concentrations in the strata of the Earth are irrefutable witness to the evolution of the chemical composition of the atmosphere and the gradual increase of oxygen.
If this actually happened to Mars, the question is how it got so oxygen once the Martian atmosphere. One possibility, according to the researchers is that derived from the decay of the surface water planet when Mars lost the protective magnetic field, resulting in ionizing solar radiation to cleave the water molecules into oxygen and hydrogen.
Due to the relatively low gravity, the Mars could not restrain the very light hydrogen atoms, but the heavier atoms of oxygen remained. Then, in response to the rock, the oxidation (oxides of iron, manganese, etc.) and gave rust image currently covering its surface.
At present, it remains impossible to confirm the scenario that once the Mars had much oxygen in the atmosphere. Although oxygen is considered a “signature” of life, the whole process of creation can be done purely geochemical way without engaging microorganisms.
The manganese oxides were discovered by the rover Curiosity in the Kimberley region of the crater Gale, which continues to explore in 2012. The other rover of the American Space Agency, the Opportunity, located on Mars since 2004, was recently also discovered oxides manganese at a distance of thousands of kilometers from Curiosity. This supports the view that oxidative conditions which favored the creation of these rocks were not locally limited, but spread all over the planet.