The Skeptical Teacher

Musings of a science teacher & skeptic in an age of woo.

Archive for January 16th, 2009

Life on Mars? Not so fast…

Posted by mattusmaximus on January 16, 2009

I just found out about some very exciting news! It seems that the hypothesis that Mars currently harbors some kind of microbial life just got a boost. Check out this article from NASA…

Martian Methane Reveals the Red Planet is not a Dead Planet


The basic premise of the article is that there are unexpectedly high levels of methane gas in the atmosphere of Mars. Because natural processes on Mars destroy methane quite quickly, for this much methane to be in the atmosphere means that something is producing it. Based upon what we know about chemistry, there are only two possible sources for so much methane – esoteric geologic processes and microbes, as in lifeforms.

Couple this with what we’ve learned over the last decade about Mars having had a much wetter (as in water!) past than we once thought, and the evidence seems to point in the direction of life. However, we do not yet know anything definitive (this is merely circumstantial evidence), and a good skeptic attempts to avoid excessive speculation in favor of critically analyzing the evidence at hand.

We do know that life is much tougher than we once thought, even as recently as 10-20 years ago, and that it pops up in many places that would surprise us. In addition, we’ve learned much about extremophiles (those surprisingly tough little critters), and recent scientific research regarding the origins of life has brought us closer to understanding how life may have arisen from non-life (what scientists call abiogenesis).

But is all of this definitive evidence of life having evolved on our neighboring planet, Mars?

In my opinion, no… not yet.

Remember that we know of two possible processes that can account for the extra methane in the Martian atmosphere: geologic processes and microbial life. That means that in order for us to be sure that there are little Martian microbes living under the surface of the Red Planet, we have to be able to rule out the potential geologic origin of that methane.

This is a good lesson in applying skepticism & critical thinking, because though I may wish for there to be life on Mars (boy do I wish it), whether or not there really is life on Mars is not up to me to decide.

The universe operates according to its own rules, which don’t take into account the wishes & feelings of sentient beings such as you and me. As I tell my students, we have to change our preconceptions & beliefs to fit the universe on its own terms, not the other way around. Only then can we really learn something about the world around us, and the best method for learning – in an honest, objective, and useful manner – about our universe is to use science.

It is unfortunate that so many people allow their preconceived notions about how they think the natural world should behave that they fail to understand that it is they who have to conform their beliefs to fit nature, not insist that (magically) nature conform itself to fit their beliefs. This kind of magical thinking is the source of much pseudoscience and woo.

So, in conclusion, is there life on Mars or out there in the vast gulfs of space? The most honest answer is, “We don’t know.”

But someday, if we work at the problem really hard and perhaps get a bit lucky, I think we’ll find out the answer.

Posted in space | Tagged: , , , , , , , , | 2 Comments »

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