Building the Nest

            I have been itching to get into the origin of life but first I want to elaborate on the environment that allowed life to flourish.
            10 billion years after the Big bang, our Solar System,which is our sun and the other planets, began to form from the collapse of a giant molecular cloud made up of mostly hydrogen. See " A Smoking Gun).This happened in the outer reaches of our galaxy, The Milky Way.
http://www.godandscience.org/images/spiralgalaxym81.jpg
            Lucky for us, our Solar System's location,within the galaxy,is a factor in the origin of life on Earth. Our Solar System rotates at the same speed of the spiral arms of the galaxy and rarely passes thru them.This means our solar system is not too close to the other stars and not affected by the intense radiation from supernovas, stars blowing up.
            Of the planets in our Solar System, only Earth has the proper environment for life to thrive. The Earth is the 3rd planet from the sun and Venus,the 2nd planet from the sun, has been called our sister planet.This is because the mass, density and volume are similar.The similarity ends there.
             Venus has no surface water and a toxic heavy atmosphere made up of almost entirely of carbon dioxide and clouds of sulphuric acid. This causes a catastrophic greenhouse affect as sunlight is trapped and cannot radiate back into space.Yet,this deadly hell is the most beautiful object when looking up at the early evening sky.
              Mars,although smaller in size and mass, is the only other planet in the Solar System that could support life but it lacks a magnetic field like Earth has, that stops it's atmosphere from being stripped away by the solar wind. Recent observations have indicated that Mars may have frozen water.It is also the best bet for eventual colonization, which may become necessary in the future , to preserve life if a cosmic catastrophe would make the Earth uninhabitable.
               The other planet I want to mention is Jupiter. It is a massive gas giant dwarfing the Earth and revolves around the sun at the outer reaches of the Solar System. I want to point out that recent observations of other solar systems, show massive gas giants similar to Jupiter BUT revolve close to the star.This is important because Jupiter's tremendous gravity protects the Earth by capturing comets and asteroids from entering the inner Solar System ,inhabited by Earth,Mars,Venus and Mercury, and flings them back out into space. This action spares us from being bombarded by comets traveling through out the galaxy. Without Jupiter comets and asteroids would collide with our planet 1000 times more frequently.
                For the first 100 million years , the Earth was totally inhospitable to life. Rain was a corrosive acid and the atmosphere of sulphurous fumes were very similar to conditions on Venus.
                Lucky for us, after about 15 million years of Earth's existence, a large object the size of a planet, smashed into the Earth throwing large pieces into near space.After 100 million years these pieces coalesced and formed our moon.This event enabled the Earth to stop wobbling and settled into a stable rotation. The moon also helped create our weather and tides. Scientist have concluded that without the moon, there would be no life on Earth. None of the other inner planets,Mars,Venus and Mercury, have a satellite.
                Now we come to water,H2O,this most essential molecule made op of elements of hydrogen and oxygen.While water may exist, according to recent scientific observations,on Mars and Venus and even the Moon, the amount is minuscule compared to the amount of water on Earth.Over 70% of the Earth's surface is covered by water.The current scientific theory is that life originated in water.It is essential for life as our bodies are made of 70% water.
               Where did it come from?Why is it so plentiful on Earth but rare as diamonds in the rest of the Solar System. Currently there are Two scientific theories: 1(Water rich asteroids and comets raining down on the early Earth). 2 There was a thick blanket of hydrogen reacting with oxides in the Earth's mantle to form lakes and seas.
                To be continued in the next post.
Origin of water