By Keith B.
We know how important water is to us…but where did it come from? The conclusions of a University of Michigan team, recently published in Science magazine, state that up to 50% of the water now on Earth may have existed before the birth of the sun, 4.5 billion years ago. The article states “water is known to form in the clouds of gas and dust of the interstellar medium (ISM) from which planetary systems coalesce.” So how do we know it’s older than the sun? Apparently, the level of deuterium found as a replacement for hydrogen in “heavy water” is the key. The amount of deuterium found in Earth’s water, although quite small, is said to be 6 times more prevalent than the “average” level of that element found across the universe. (Please don’t ask me how anyone knows that.) Anyway, the enrichment of deuterium only happens in certain conditions. Those conditions are very cold (only ten degrees above absolute zero) plus oxygen and ionizing radiation. All of these are said to be present in the ISM. The theory follows that after the sun was born, the remaining ISM creates a protoplanetary disk spinning around it. The U of M team created models and computer programs that simulated the conditions in that protoplanetary disk, showing that they wouldn’t destroy the “heavy water” it came with, but also wouldn’t produce much more. Therefore one could conclude that our water, because of its % of heavy water, came from the ISM before the sun was born. All this is somewhat mind-boggling.
While once we thought that water might be somewhat unique to Earth, it is being found in several “new” places. azdailysun.com reports that
NASA’s Curiosity rover has discovered evidence of a vast lake in Gale Crater that potentially lasted millions of years—findings that may contradict the idea that much of the planet’s water reserves were held only in ice or underground, and made only transient appearances on the surface. The new results from studying rocks at the base of Mount Sharp (the 3-mile-high mound in the middle of Gale Crater) points to a lake that filled and drained over tens of millions of years and that could have spanned the 96-mile-wide crater, scientists at Jet Propulsion Laboratory in La Canada Flintridge, Calif., said. And the sediments deposited in this lake could be what helped form Mount Sharp in the first place. ‘The puzzle pieces are coming together,’ Michael Meyer, lead scientist for NASA’s Mars Exploration Program, said in a press briefing. The findings from Curiosity, known formally as the Mars Science Laboratory, show that water could have lasted long enough for microbial life potentially to emerge, the scientists said.
Maybe there was life on Mars and maybe someday we will be sending it back.
What is interesting, at least to me, is that once again water shows up at the very beginning of everything and at the center of our lives. We are constantly updated with news that includes floods, droughts, blizzards, monsoons and other water related phenominae. We are developing new and improved ways to produce fresh water from salt water, and to purify and recycle the water we have on the Earth. Many of us are drawn to water; enjoying swimming and boating. We find it relaxing and even rejuvenating to just sit at a beach, or near a lake or stream. Now we think water might just be floating around the universe in giant clouds of gas and dust, making it possible for life to exist potentially on many planets in many solar systems. Amazing!