The Chicken, the Egg, the Big Bang, and Water

By Dr. Mark LeChevallier – August 16, 2013 – Comment

Which came first – the chicken or the egg? Or more appropriately for this blog, which came first – water or the Big Bang? Do you know where water originally came from? Most likely, it’s probably not something you ever stopped to ponder, but the nonetheless, an intriguing topic. A recent Smithsonian article tackles the mystery of H20. (I guess we weren’t the only ones thinking about the age of water last month!)

The article explains that the story of water starts some 13.8 billion years ago with the Big Bang. Within the first few minutes after that major event, the particles that spewed forth from the blast mixed together to form the first atomic nuclei. In particular, creating a lot of one of the simplest forms of nuclei – hydrogen, a building block for water.

Fast-forward about a billion years after the Big Bang and you’ll find a universe plentiful with stars. Within their interiors are nuclear furnaces, fusing together these simpler types of nuclei into more complex elements – enter Oxygen, the other part of our water equation.

So now that the two elements are floating out in space and combining to form water, how does that water make its way to Earth? In the early days, our planet had high temperatures and lacked an atmosphere. Surface water would simply have evaporated. So water needed to come to the planet from somewhere else.

Astronomers point to asteroids and comets as the most likely source. Both celestial bodies can contain ice and may have been large enough to deliver oceans worth of water to Earth. But the debate as to whether it was an asteroid or a comet that collided with Earth and left water in its wake still rages on. So maybe the question really is, which came first – the comet or the asteroid?

We know that water is a valuable, life giving, but limited resource; so unless we have any more giant comets (or asteroids) hit the Earth, we need to prudently manage the resource that we’ve got!  So next time you gulp down that glass of cool refreshing water, give some thought to its cosmic origin.