NASA’s Curiosity Rover and satellite images reveal that Mars may have had water and high levels of oxygen. The Rover has been taking rock samples at Gale Crater and analysis showed high levels of manganese and manganese oxide, which suggests that the Red Planet held high levels of oxygen. These findings have also been discovered at sites thousands of miles away.
The recent research shows that unlike Earth where the atmospheric oxygen was caused by microbes, on Mars it may be the result of water molecules being split by solar radiation.
Dr. Nina Lanza, a planetary scientist at Los Alamos National Laboratory in New Mexico and study lead author says,
The only way on Earth that we know how to make these manganese materials involve atmospheric oxygen or microbes.
These high-manganese materials can’t form without lots of liquid water and strongly oxidizing conditions. Here on Earth, we had lots of water but not widespread deposits of manganese oxides until after the oxygen levels in our atmosphere rose due to photosynthesizing microbes.
One potential way that oxygen could have gotten into the Martian atmosphere is from the breakdown of water when mars was losing its magnetic field.
The theory is that billions of years ago, Mars’ magnetic field failed and without protection, the surface would have been hot with intense solar radiation. This would have slip atoms and split water into hydrogen and oxygen. In this thin atmosphere, the hydrogen gas would have evaporated leaving the heavier oxygen to react with other compounds, like manganese oxide in the rocks and red iron oxides in the soil.
The study states,
Based on the strong association between Mn-oxide deposition and evolving atmospheric dioxygen levels on Earth, the presence of these Mn-phases on Mars suggests that there was more abundant molecular oxygen within the atmosphere and some groundwater of ancient Mars than in the present day.
These results suggest that the evolution of the Martian atmosphere may have been more complex than previously thought.
It’s hard to confirm whether this scenario found for Martian atmospheric oxygen actually occurred. But it’s important to note that this idea represents a departure in our understanding for how planetary atmospheres might have been oxygenated.