What’s This About Methane On Mars!?
I have had at least a few people ask me directly “what exciting stuff is there left to discover in science?” Other than the obvious fact that there are definitely exciting answers to questions we haven’t even conceived of yet, there are also many major scientific mysteries answerable in this lifetime. I do not look think badly of these people, they likely haven’t had the exposure to learn about cutting edge modern scientific mysteries. It is also true that many of these mysteries, like those potentially answered by the LHC, require a deal of background knowledge to wrap your mind around. Nevertheless a few hours on wikipedia browsing major concepts in physics and astronomy is all anyone needs to appreciate the awesomeness of things like black holes, dark matter, entanglement, supernovae, exo-planets or the Higgs Boson.
This blog entry is about what I consider possibly the most exciting scientific question easily answerable in my lifetime. That question is “What’s with the methane on Mars!?”
What is so exciting about some gas leaking from Mars you might ask? First a little background. Methane on Mars was first discovered by a team at NASA back in 2003 using infrared telescopes fitted with spectrometry devices that break down incoming light into it’s constituent spectrum and can infer chemical composition from the signature or absorbed wavelength. This methane is being released annually (Martian annual) during the warmer periods at a number of locations. The gas is released in a series of plumes which can release as much as 19,000 tons of methane each!
So what does this all mean? Well we begin by considering all possible explanations for these methane plumes that scientists consider plausible. A likely explanation is that some geologic process is going on underneath Mars that is creating this methane. The only known way this could be happening on Mars is if water, carbon dioxide and the planet’s internal heat are converting iron oxide (rust) into serpentine minerals (common rock-forming hydrous magnesium iron phyllosilicate minerals). One major stumbling block with this explanation is that Mars is not thought to be geologically active and the required heat has not yet been found. It is possible that pockets of methane created in aeons past are stored beneath the surface and released annually as fissures form from cracking permafrost but this adds in another layer of complexity. There are other geologic questions that need to be answered before a complete explanation could be established and any such answer would still provide fascinating and as yet unknown information about ongoing activity on the Red Planet previously not thought to exist.
Another explanation, recently discounted by published research suggested that the methane might be left over on Mars from meteorites. Calculations have shown that the amount of meteorites needed to continually maintain the levels of methane found on Mars is far beyond what could be considered possible. There are other gaping holes in this hypothesis, such as why would the methane be confined to a few discrete pockets and why is it only being released annually. After considering the possible explanation of geologic activity and the unlikely explanation of meteoric activity we are left with one other major hypothesis.
That’s right, scientists are very seriously considering the idea that the methane on Mars is being produced by subsurface microbes. Some of the earliest lifeforms on Earth were microbes that produced methane from hydrogen and carbon dioxide, both of which are found aplenty on Mars. It could be that these microbes are several kilometers under the surface, releasing methane which rises to the surface and gets trapped each year under the permafrost only to be released in jets as the frost melts in the Spring. The same areas on Mars that the plumes are rising from have shown evidence of current flowing water. That’s not to say flowing water as in streams and rivers, more like tiny trickles that move a few meters (or less) and immediately freeze again.
The truth about how likely this hypothesis may be is that we honestly have no idea. One massive problem when working with a sample size of 1 (as in life from one origin) is that we aren’t able to extrapolate anything meaningful. It may be that any planetary system with similar conditions to early Earth has a high likelihood of developing life or we may have been an astronomically unlikely fluke. At this point we cannot say either way. The implications for Biology, Astronomy, Chemistry and society if this methane does turn out to have a biological origin are of course staggering. I don’t think I really need to explain just how much of a game changer it would be if we found another origin of life. All we need to do to answer this amazing question is sending technologies capable of measuring and collecting deep below the Martian surface. While this isn’t something that will be happening in the next 5 years there is a strong likelihood or it happening in the next 10-20.
So if you ever had any doubts about whether there are genuine exciting mysteries in science to answer I hope to have dissuaded you of such a notion. It didn’t even require much background knowledge, even I’m able to summarize it! This is only one of the many mysteries out there and the one that I consider most powerful if true. Even if it doesn’t turn out to be life we will have still learnt something fascinating and brand new about how our not so distant Red Planet brother isn’t quite as dead as we first thought.