Streams in the Martian Desert


Recently, a group of NASA scientists announced that the Mars Reconnaissance Orbiter had taken close-up pictures of Mars that give convincing evidence that, in some places, the planet’s surface is active with liquid trickles flowing downhill. What was thought to be impossible proved to be possible. As you read this, briny water may be flowing on Mars.

These trickles are so small that they were hard to see. It took years of thought and some clever computing to increase the resolution of the instruments on the Orbiter. Only then could those instruments confirm that dark streaks on the Martian surface are associated with liquid H2O. This is a triumph that resulted from looking closely and carefully with scientific rigor, and that’s another reason for scientists to be excited. Hard work paid off; it lead to a solid finding.

Liquid water is so closely associated with life that the presence on Mars of the former allows the possibility of the latter. It’s hard to communicate exactly what this means in a single sentence or a clickable headline. When the NASA scientists say “life on Mars,” they’re thinking of microbes. But in a more general context, “life on Mars” evokes H.G. Wells, John Carter, Elwin Ransom, or Tim Burton, depending on your taste in literature. In this context, the mere possibility of microbes may underwhelm. As The Onion’s headline put it, “Nation Demands NASA Stop Holding Press Conferences Until They Discover Some Little Alien Guys.”

But for me, this calls for wonder, not cynicism. The NASA scientists are right to be excited, because even the simplest forms of life are amazing. Upon close inspection, even the most common microbe reveals an intricate, dynamic work of art. If the possibility of finding such a microbe has increased, our universe has become a little more detailed, and a little more special.

Consider the microbes of the Martian fields (if they exist). With only wisps of an atmosphere above and dry dirt below, they must gather enough energy and matter to organize themselves against physical forces that would tear them into bits and chemicals like perchlorate that to most organisms are dangerous toxins (but to a select few microbes are like food).  Martian microbes must record their organization in a chemical crystal, probably a one-dimensional polymer like DNA, and reproduce themselves. They must move and change, so they need to be made of matter that moves and changes as well—in short, they need to be mostly liquid.

But this Martian liquid is exposed to the sun’s energy in such scant amounts that it has taken us years of searching to find it. If they exist, these microbes gather all they need through what must be ingenious biochemistry. How do they do it? I have no idea. That would be worth serious investigation and expense.

And yet, are you not worth more than many microbes?

The prospect of microbial life on Mars should enhance, not diminish, our amazement at the giftedness of our own planet. The streamlets on the Red Planet are a gift that might support life. Our planet has been given many, many more gifts that support life exponentially more varied and capable. Where Mars has rivulets, we have oceans. Oceans are very important to life, inside and out. Your blood is itself a portable, salty ocean that nurtures your cells.

On Earth, water promoted evolution of life and of geological processes. As the oceans reacted with the earth for billions of years, they created new minerals so that the Earth is the most geologically diverse place in the solar system.

In a recent study, geologist Bob Hazen and colleagues surveyed beryllium minerals and calculated that the specific combination of minerals on Earth is “unique in the cosmos.” If one of these rare minerals served as a specific catalytic surface for life, then life itself may be a rare gift; or if a common mineral served that purpose, then life may be a more widely dispersed gift; or if conditions long ago on Mars served that purpose, life could have traveled here on a stray meteorite. So far, we don’t know, but we live in a universe where we can find out with repeated experiments.

The sequence of chemical and mineral gifts, reacting in liquid oceans, has culminated in the human brain, the most complex object in the known universe. One of these complex objects is undeniably and irrevocably yours, giving you the power to read this sentence, to map distant planets in your head, and to choose to wonder about life on Mars and what it means.

When NASA scientists used their brains to find something true—in this case, flowing water on Mars that was a good use of the gifts they’ve been given. As a Christian, I start from the fact that God is the source of all life and of all the gifts that make that life possible (even on Mars, or in the next galaxy over). As a chemist, I believe that he gave us chemistry as a secondary gift that unfolded itself through consistent and understandable laws to give us these other gifts today. The consistency that makes the universe comprehensible is itself a gift.

So when I found out that the gift of liquid water extends to a planet once thought to be barren of that gift, my response was not disbelief or “press conference fatigue,” but gratitude, both for the small gifts there and the greater gifts here. My second response is the impulse of curiosity. We should seek more gifts and find out more about this transiently flowing Martian environment. The good news is that, given the rich and varied nature of the universe and the generous nature of its Creator, I expect that more gifts are in store.


Notes & References