Blue Planet

Our reading assignment reminded me of  a blog post I was going to make about two months ago.  I was still having trouble getting into my account so I never got around to actually doing it.  I watched a television show called "Blue Planet", on the Discovery channel, it was about deep ocean hydrothermal vents(Chapter 13 page 370).  Extremely hot( 400 degrees C according to our book Earth: An Introduction to Physical Geology by Tarbuck, Lutgens, and Tasa) mineral enriched water pours out of these vents and when it interacts with the regular sea water it appears as black clouds so the vents have been given the name "black smokers".  The water is under too much pressure to boil, in case you were wondering.  What I found most interesting was all the marine life down there where the sun does not shine and the pressure would squeeze you or I into a relatively tiny lifeless ball.  It seems to me that if life could exist down there it could exist on many worlds that were previously thought to be uninhabitable.  The show had footage from a deep sea submersible and narration by a guy who rode down in it.  One of the parts I remember had him talking about the clear plastic "window" on the craft.  Apparently the melting point of the plastic was lower than the temperature of the water coming out of the black smokers so in addition to the many perils of high pressure environments they had to keep a safe distance to keep from being crushed.  The life down there is incredible.  Many of the creatures are bio-luminescent, mostly whites, greens, and blues, but there is one predatory fish that generates red light.  Most of the creatures cannot detect red light so it is invisible to its prey. I would not have thought life would find light so important down there when there are so many other ways of detecting your environment but these creatures shine like hundreds of glow sticks.  At one point they showed an undersea "lake" made of greater than normal salinity water.  The narrator said when they tried to enter the lake they bounced off it as though it were made of rubber.  Something about its density or maybe it was the salinity or surface tension or all of it made it impassable(nothing is impossible).  Another creature down there had the biggest teeth for its size of all the life on Earth.  Anyway, if you like pretty lights and/or grotesque beauty check out "Blue Planet".  There is a lot of material on the Discovery channel site.