| Did you read the article? > The presence of methane is significant because the gas decays quickly. If there were microbes on these spacecrafts and probes, there would have to be a massive rotting carcass producing a size-able amount of methane sitting right in front of the gas analyzers to throw off the instruments. It's more likely that the measurements of methane on Mars are (A) negligible, and (B) are naturally occurring. Especially given that methane on Earth (at any given altitude) is a about 1800ppb [1]. Contrasting with the probes *average measurements of 4ppb. I'm no scientist, however I am an avid science reader. Here's a great summary quote from Wikipedia on the chemical relationship of methane and carbon dioxide: > As methane rises into the air, it reacts with the hydroxyl radical to create water vapor and carbon dioxide. The lifespan of methane in the atmosphere was estimated at 9.6 years as of 2001; however, increasing emissions of methane over time reduce the concentration of the hydroxyl radical in the atmosphere. That's just the nature of the methane here on Earth. [2] But you can probably imagine the relationship is about the same on Mars. In fact, you can read a summary about the chemical relationship here in this abstract. [3] But I would recommend some serious problem solving to piece together what this piece is trying to communicate... Consider this hypothesis about Mars: - Organic matter may have existed > now no longer exists. - Methane was once at Earthen levels > now no longer is. - Carbon dioxide was once at Earthen levels > now it exceeds it. - Methane decays into carbon dioxide. - Is it possible that organic matter continues to exist on Mars in a seasonal/irregular pattern? What does the data suggest to you /u/sholladay? That these sensors were broken/contaminated? Or that we are trying our best to parse Mars' veiled past? It's not irresponsible to consider contamination plainly because it's irrelevant — the tenants of this hypothesis are grounded in chemical observations, not biological observations. [1] https://www.nova-gas.com/analyzers/methane [2] https://en.wikipedia.org/wiki/Atmospheric_methane [3] https://www.ncbi.nlm.nih.gov/pubmed/11539176 |