December 11, 2012

The Search for E.T. Continues...

As it happens I have the time, the energy and the will to resume my blog, so I’m coming back to this. What better way to begin again than to talk about SPACE!

So pretty

NASA always has interesting news, even if its just interesting to me. Of note are two news bits from extraplanetary probes, the Mars Curiosity Rover and the Messenger satellite. The Curiosity rover turned heads when the lead scientist announced they may have found something that would be ‘one for the history books’ only to renege on said statement. What was found was complex chemistry with carbon in it (methyl chloride to be precise) but the exact origin of these compounds, and whether they’re of martian origin, is still up for debate. The current theory is that carbon from the rover reacted with choride in the martian soil, forming what is is technically an organic compound, but nothing groundbreaking.... Like what was found on Mercury by the Messenger probe

Much more noteworthy than a martian false alarm is the discovery of almost 1 trillion metric tons of ice from 50 cm to 20 meters deep on Mercury. For context that’s 1100 cubic kilometers (around 260 cubic miles) of 
ice this is roughly the same size as the Arctic ice cap . The ice is kept safe in the permanently shadowed poles of Mercury which never receive sunlight due to the planets almost perfectly vertical axis. Some of this ice is exposed and remains as -223 degrees Celsius (that's -370 Fahrenheit), but more interestingly there’s ice where there shouldn’t be, in fairly warm areas above the freezing point. Ice here appears to be insulator by ‘strange dark insulator’ that does seem to be comprised of a complex mix of  organic compounds (including amino acids sugars and proteins), the building blocks of life. Scientists at NASA were quick to say that life on mercury was a long shot, but the data gives hope that life might be found in even the most extreme circumstances outside of Earth and that the universe is a much soggier place than originally expected.

So why the big hunt for water and organic compounds? Organic compounds make sense, we’re made from long chain carbon compounds, and its unlikely that life would choose another method to base itself from. Carbon can form long complex chains, the closest thing to carbon chemically is silicon, but silcon doesn’t form long complex chains. Any silicon based life would be simple, if possible at all. Silicon is a more common element on earth than carbon is, so presumably if it were possible or sustainable it would’ve likely been done.

So why water? Water is often said to be the key component to life, but it’s seldom explained why. Water is an ionic mixture so it can hold many different compounds, salts and other metals, and more importantly it can hold some organic compounds in suspension. Water acts as a solvent, so it can act as a bridge helping various compounds react with eachother, and given it's ionic nature it keeps predominently nonpolar molecules (i.e. most organic molecules) close together, close enough so that they can react and do the processes required for life to occur
. Almost every animal, plant and microbe on the planet has it, even when the environment would dictate that it’s not feasible. Liquid water’s scarcity in the universe however brings up questions of other solvents, like ammonia, would be possible.

The search for life is ultimately a search to try and understand the universe. Are we special snowflakes, an oddity in an otherwise lifeless void. Are we perhaps the most intelligent lifeform out there? Or are we just one among many.

One way or another we will find out. I personally hope it’s sooner rather than later

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