A few years ago, scientists discovered water on the moon; they told us this reservoir of water which was a total surprise, must have arrived on comets. However, now they are changing their minds. Apollo 15 and 17 brought back rocks from the moon and new research suggests that the moon’s water is from Earth!
The moon received its water from Earth via meteorites, apparently. It's is now believed that the moon was formed from debris knocked off Mother Earth by a collision with a Mars-sized body. This is known as “The Big Whack” and happened about 4.5 billion years ago.
It wasn't thought any water survived the impact, but this newly published study suggests some water did survive because the collision formed a barrier of hot gases that protected the water as chunks of Earth sailed away in the explosive collision.
Fast forward to 2013: Earth’s supply of fresh water is limited. As the global population rises dramatically, the demand for food – and the water that produces it – grows by leaps and bounds. Globally, farming accounts for 70 per cent of our withdrawals from this fixed amount of water.
Water tables are falling in many parts of the world. Himalayan glaciers are shrinking and will continue this massive melt, projected to be gone in less than one hundred years. Glaciers worldwide are rapidly shrinking. There are a few exceptions but natural water storage in the Earth’s glaciers is diminishing drastically. Many great rivers now have radically reduced volume (flow) and sometimes salt water flows in from the sea, degrading the river even more. For instance, Bangladesh is suffering from the diversion of Ganges River water and increased salinization.
Underground aquifers in many places are shrinking so rapidly that NASA satellites are detecting changes in the Earth's gravity. India faces a 50 per cent lag in water availability relative to demand by 2030; global availability of useable water may lag behind demand by as much as 40 per cent.
It is clear that in the not so distant future, fresh water will be as precious and expensive as oil, if not more so.
Sixty years ago, the world's population was about 1.25 billion people; then came the Green Revolution, with its high-yielding crops which depend on fertilizers and irrigated farming. Global populations skyrocketed to seven billion people with a projected nine billion people by 2050.
The problems are acute, especially in arid areas with growing populations, where boreholes and aquifers are thought to be the answer. However, these are short term solutions exceed the replenishment rate. Mexico City with 20 million inhabitants is sinking and Bangkok, Buenos Aires and Jakarta, have extreme pollution and rising salt levels combining with the growing population’s growing demand. In China, deep groundwater levels have dropped as much as 295 feet in places and sink holes are common.
We have penetrated Earth's surface with boreholes which deplete a resource we humans cannot live without. Now we stand at the threshold of a scenario in which catastrophe looms on every side. Impending doom lurks realistically just around the corner as water supplies fail. Tens of thousands of people even now cross national boundaries to find water. What won’t people do to obtain fresh water? Futurist after futurist warns that water wars are a certainty in our future.
Ninety-seven point five per cent of all water on Earth is salt water, leaving only 2.5% as fresh water
Nearly 70% of that fresh water is frozen in the icecaps of Antarctica and Greenland. Now much of Earth’s ice sheet is melting, running into the ocean and becoming saline. Most of the remainder of our fresh water is present as soil moisture, or lies in deep underground aquifers as groundwater which is fast-dwindling due to human demand.
One per cent of the world's fresh water (~0.007% of all water on Earth) is accessible for direct human uses. This is the water found in lakes, rivers, reservoirs and those underground sources that are shallow enough to be tapped at an affordable cost. Only this amount is regularly renewed by rain and snowfall. However with climate imbalance, all too often there are long droughts or severe floods in which the water becomes contaminated as it washes over the land and then is lost into the oceans.
In the future, can the moon’s water be somehow transported back to Earth? There might be ethical questions here – is the moon really a dead world or has this reservoir of water produced life of some kind? Does Earth have a right to this water?
And, water is notoriously expensive and difficult to transport. California, for instance, spends billions of dollars transporting water from one location to another.
However, what if we can find a way to transport the moon’s water back to Earth? It was our water originally, after all. This might sound ridiculous but when the day comes that Earth runs out of useable water, any far-out idea might seem worth a try.
Will the water which was blasted from Earth in the Big Whack 4.5 million years ago, be coming home?
We are not sure how much water is available on the moon but it seems to be a fairly decent amount. Perhaps someday, we’ll deplete that water, too. We humans must get our population growth under control or we will breed ourselves right out of an inhabitable planet.