NASA’s Mars Curiosity Rover has detected chemicals in Martian rocks that suggest that the red planet had more oxygen in its atmosphere in the past than it has now.
Scientists reportedly discovered high content of manganese oxides in the rocks with the help of the rover’s laser firing instrument.
The recent spate of Curiosity findings, which includes proof of ancient lakes flourishing on the planet and the new discovery of more oxygen in its early atmosphere, reveal how Earth like Mars was once.
The new study also adds another important dimension to the previous clues found about the red planet’s atmospheric oxygen in the past. The manganese oxides were detected in the mineral veins of an area that was dated to an ancient environmental timeline.
Therefore, from that context, the researchers interpreted that the higher level of oxygen on Mars coincided with a time when groundwater was present in the Gale Crater.
“The only ways on Earth that we know how to make these manganese materials involve atmospheric oxygen or microbes,” said Nina Lanza, planetary scientist from New Mexico’s Los Alamos National Laboratory.
“Now we are seeing manganese oxides on Mars, and wondering how these could have formed? These high manganese materials cannot form without lots of liquid water and strongly oxidizing conditions. Here on Earth, we had lots of water but no widespread deposits of manganese oxides until after the oxygen levels in our atmosphere rose”.
In the geological record of our planet, the occurrence of high levels of manganese oxide minerals is an important proof of the change in Earth’s atmospheric make, from comparatively low oxygen to an oxygen rich one.
Therefore, the scientists believe that the prevalence of similar types of components on Mars indicates that there was an increase in oxygen levels there too, before it declined to the present status.
According to the researchers, the oxygen rich environment in Mars formed due to the breakdown of its water when the planet was losing its magnetic field, at a time when water was more abundant there. The water molecules started getting split into oxygen and hydrogen due to the ionizing radiation caused by the absence of a protective magnetic field.
Mars wasn’t able to hold on to the hydrogen atoms, owing to their light weight but the heavier oxygen atoms remained behind and went into the rocks and formed the rusty red dust that can be seen on the surface today, and which gives the world its name of red planet.
Incidentally, the manganese rich materials have been found in the Kimberley region of the Galle Crater, and this is not the only place as there is evidence of the mineral in areas thousands of miles away from the rover too.