NASA's Curiosity rover continues to make discoveries that challenge our understanding of the Martian environment. The latest strange puzzle that taxes scientists is the variation in oxygen levels on the planet's surface, which discovered Curiosity's portable chemistry lab, Sample Analysis at Mars (SAM).
In his journey around the Gale crater, curiosity discovered the Martian atmosphere has a composition at the surface of 95% by volume carbon dioxide (CO2), 2.6% molecular nitrogen (N2), 1
.9% argon (Ar), 0.16 % molecular oxygen (O2) and 0.06% carbon monoxide (CO). Nitrogen and argon levels follow a predictable seasonal pattern and change relative to the amount of carbon dioxide. However, the oxygen levels did not match the expected pattern and increased by as much as 30% in the spring and summer.