The Last Word On Nothing

The first memory I know for sure is the smell of rain. I remember a screen door with holes in it big enough to let in a hummingbird, and outside I could see blue bellies of clouds over a dirt road. I can only figure it was somewhere in Arizona where I was born.

I’ve always been a water person. Even though I partly grew up in the desert — or because of that — I am mesmerized by its presence. At the root of what I know is rain.

Whenever a new discovery arrives, liquid water found on the surface of Mars or a shell of water vapor found around a quasar at the far end of the visible universe, I send up a private hooray! We’ve done it again, we’ve found more water. The media usually celebrates these finds along with me, which I take as proof that I am not alone.

Last week, NASA confirmed evidence of liquid water on Mars. Fluid erosion and deposition patterns appear to be ongoing, increasing during warm seasons, decreasing in cooler seasons. It is a melt and flow pattern, evidence that Earth is not alone in the solar system with liquid water.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

Though scientists are ostensibly scanning the universe for water in case we might want to live somewhere else or find something else alive, I believe the urge goes much deeper. We are looking for water because it is the oldest, most compelling classical element around us. As natural science author Loren Eiseley wrote, “If there is magic on this planet, it is contained in water.”

Do you sometimes fan your fingers through faucet water at the sink lost in the way it pools, leaps and falls into beads? Do you pause at storm drains or manhole covers when you hear a rumble and splash in the dark below? Water casts a spell. Even where it runs along a gutter from a car being washed uphill, you watch it as if it were an animal probing ahead, going around cigarette butts or pine cones.

Considering the range of temperatures possible in our solar system (the hot side of Mercury at 465 °C, Neptune at -224°C), Earth lies within a unique range. The average temperature of our planetary surface is 16°C. At 0°C water freezes and at 100°C it boils. Our average is seated neatly within the brackets, on the cooler end so as not to be uncomfortably hot. 

Zircon crystals 4.4 billion years old have been found in Australia containing minerals that could only precipitate out of water. This comes from an epoch of heavy asteroid bombardment from before the earth had any known life. But it did likely have oceans. To say water has been here since the beginning would be an understatement.

A tremendous amount of water vapor was discovered in 2011 around a supermassive black hole 12 billion light years away. This volume is 140 trillion times more than the earth’s oceans combined. Appearing 12 billion years ago, it is the oldest known water in the universe.

Hydrogen is the most basic element, one of the first things to come out of the Big Bang. Oxygen is created by nuclear reactions within stars. When the two elements combine in space, H₂O is formed. A planet like Earth, or Mars for that matter, is one of the few places where conditions are right for this water to appear in liquid form. This is why when it rains, I go outside. I can’t get over the uniqueness.

Mars did have running surface water under warmer atmospheric conditions in the past. The surface holds evidence for a full hydrospheric/atmospheric cycle that would have included rainfall. Under todays colder, drier conditions, frost has replaced rain. As far back as the Viking II lander in the 1970’s, frost was seen on the ground on some mornings, and fog has been known to drift into craters and canyons. These are all forms of water, faint remnants of an ancient hydrospheric cycle.

It may help that I am from the desert. My love for water has been sealed by aridity. But it is an attraction more universal than what part of the earth one is born to. Our excitement when we find it on Mars, or anywhere else, suggests to me the smell of rain might be the oldest memory for many of us. It is one classical element that we will follow anywhere. And one element that seems to be everywhere.