When compared to the mass of the planet, Earth’s oceans are a very thin film, like fog on a bathroom mirror.
Even though water covers 70 percent of Earth’s surface, it makes up a very small fraction of the planet’s overall bulk. Earth is mostly rock and iron; only about one tenth of one percent of the planet’s mass is water. Earth’s massive iron core generates the radiation belts that protect us from harmful effects from both the Sun and deep space. If it wasn’t large, it wouldn’t protect the planet.
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Is Earth unique? Clearly there are no planets in the distant solar systems that we’ve been able to probe that replicate the life-giving environment that we enjoy. The secret to that environment is abundant liquid water.
Earth’s water isn’t just on the surface. Studies have shown that Earth’s mantle holds several oceans’ worth of water that was dragged underground by plate tectonics and subduction of the ocean seafloor. Earth’s oceans would disappear due to this process, if it weren’t for water returning to the surface via volcanism (mainly at mid-ocean ridges). Earth maintains its oceans through this planet-wide recycling system which also takes carbon out of the cycle and subducts it back into the interior of the planet.
Whether you take the course of some scientists like Dr. Carl Sagan, who felt that God only existed in the minds of men, or you take another approach, the mechanism supporting the life that we enjoy is exceptionally complex. Examining its complexity inevitably leads to a sense of humility. Appreciating the value of life in general should bring us full circle to appreciating ourselves and those around us more — but human insecurity doesn’t seem to allow it without a lot of effort.
Apollo 8’s Christmas Eve Message (submitted below for your recollection):
“The Good Earth”
"Water is not a luxury of Earth, in fact, it is the most abundant compound in the universe because it is composed of the first and third most abundant elements, hydrogen and oxygen, respectively. However, water in liquid form is a special feature of Earth. It is usually present as vapor or ice in the Solar System. After the formation of the Solar System most of the water ended on the farthest planetary bodies locked as ice in their surface or interiors."
phl.upr.edu/library/media/liquidwaterinthesolarsystem
The secret of liquid water on Earth has to do with very complex tectonic plates that store vast quantities of liquid water in the interior of the planet. Mars could have kept its water in liquid form if it had the sort of structure that Earth does.
All one needs to do is stand alone on the back of a ship on the ocean on a dark night. When you do, you really understand how insignificant we really are. That is truly a humbling experience.
I can recall the experience myself. It puts things into perspective.
Thank You Doctor LL.
We are the recipients of magnificent bounty that we need to be reminded of from time to time, my friend.
Dark nights on the ocean an be not so dark.
Even a clear moonless light is illuminated by stars and often bioluminescence in the water. However during a storm with a dark sky, it's as dark as a — ok, you know.
Very Interesting, truly.
fascinating!
have you ever watched the BBC Planet Earth series? It's phenomenal and beautiful.
Sometimes it's easy to take the Good Earth for granted.
I don't think that I have. I'll have to watch out for it. Thx.
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