Water, water everywhere.
Space probes have found water on the supposedly arid moon and on frozen Mars as well. And where there’s water, there could be life.
Here on Earth, where the stuff is so abundant that most of the time we take it for granted, water may eventually become the source of energy that powers our post-petroleum civilization.
Finding water on the moon was a big surprise, because the airless moon has always been considered utterly arid. But NASA’s Moon Mineralogy Mapper, riding on India’s Chandrayaan-1 lunar probe, has detected water and hydroxyl (OH) molecules embedded in wide swaths of the moon’s surface dust.
It’s not a lot of water — about one quart per ton of surface material. Still, that represents a precious resource. No one expects to find life on the moon, but if (or when) humans return there to build permanent bases, water will be invaluable for life support.
Mars is a different story. Life might have once existed on Mars. It might even still exist there.
Today Mars is a frozen wasteland from pole to pole, with only a wisp of atmosphere. But those poles are covered with ice caps, a mix of frozen carbon dioxide (dry ice) and frozen water. And the landers and orbiters that have been studying Mars have found abundant evidence that once Mars was warmer and wetter than it is today.
There was once a good-sized sea on Mars, and rivers. Today that water has seeped underground and frozen into permafrost.
Life needs liquid water, not ice or permafrost. If there’s life on Mars today, perhaps microbes living underground, it would need liquid water to sustain it.
Last month, NASA’s Jet Propulsion Laboratory reported that the Mars Reconnaissance Orbiter has found new evidence of water ice just below the surface of the ground. Five brand-new craters, caused by recent meteor impacts, have exposed bright ice that had been covered by a surface layer of rusty sands.
Shane Byrne, of the University of Arizona, speculates that the ice indicates liquid water was flowing on Mars perhaps as recently as a few thousand years ago.
On Earth, some microbial organisms living underground get their water from melting ice. Could the same type of critters be living on Mars today?
Here on Earth, water may well become the fuel of the future. Water contains hydrogen, and hydrogen can be burned in internal-combustion engines. It yields more energy than gasoline and its exhaust product is nothing but water. Hydrogen can also be used to power fuel cells for electric automobiles and other clean, electric motors and heaters.
But splitting the hydrogen out of the water molecules is a tough task. It takes a lot of energy.
Yet green plants have been splitting water quite easily for several billion years. They use the hydrogen to build carbohydrate food for themselves and release the oxygen as an unwanted waste product. You and I, and all animal life, live off that “waste” oxygen.
Green plants use the energy of sunlight to split water molecules. Can we learn to do the same?
MIT professor Daniel Nocera and his associates have produced a catalyst that does just that. Nocera’s catalyst allows the scientists to split water molecules into separate hydrogen and oxygen atoms, using ordinary sunlight as the input power.
If this process can be used on an industrial scale, hydrogen fuels may become cheap and abundant enough to begin replacing gasoline and all the other petroleum products, natural gas and coal. The era of fossil fuels will come to an end, and the pollution and greenhouse warming caused by burning fossil fuels will end with it.
Water. And sunlight. Clean and green.
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Personal note: I want to thank all the many, many people who have sent condolences over the death of my wife, Barbara. Your notes and cards have been heartwarming and often brought tears to my eyes. I wish I could thank each of you individually. Please understand that I deeply appreciate your sympathy and your kind words about the woman I love.
Thank you, one and all.
Naples resident Ben Bova is the author of more than 120 books, including “The Green Trap,” a thriller about developing hydrogen fuels. His Web site address is www.benbova.com