Originally posted by KellyJay
It is basically what I read other places, thank you for sharing!
Think about what we have discovered about some of the moons of Jupiter and Saturn, where some of them, although something like the size of the moon, sports perhaps 60 MILE deep oceans. Europa is one of them. More water on that moon than all of Earth.
The hint here is they are closer to the asteroid belt and just co-incidentally have much more water than Earth. Not a coincidence.
Planets that form close to the sun, even though they are in the so-called goldilocks zone where liquid water can exist, during the protoplanet phase of planet production, they go through intense bombardment.
The Earth getting whacked by a mars sized planet is said to have created our moon from the debris slung into orbit, so powerful was the impact, and in fact the core of our planet is a lot bigger than it would have been if that planet had not collided with the very early Earth.
The core of the planet that hit us, being much denser than the rock of the mantle and so forth, literally melted its way deep into the center of the Earth and combined with the existing core which is one reason we have tectonic activity today. If it had not been for the extra core material we would have most likely lost the ability for continents to form and continue to break up and reform, which helped life to evolve by forcing changing environments to stress and test whatever life forms were about those hundreds of millions of years ago.
All that due to the fact that a planet whacked into Earth.
The gist of all that is when these kind of events happen, there will be zero water since all it takes is a bit over 100 degrees C and no more water, its now steam and will disappear into space from the violence of those collisions.
So all things being equal, the inner planets would be forever void of water. Enter the comets and asteroids.
They formed out past the goldilocks zone, where water could never be liquid unless it was involved in some kind of collision with another icy body and there could be liquid for a few minutes but it would quickly lose heat and become ice again where most of that would have just gone into space and disappeared from the scene.
So water forming from the dust belt that surrounded our protostar which became Sol would have copious amounts of water in the cloud surrounding the star, spinning in the combined orbit of trillions of particles, small rocks and so forth, rocks which crunch together to make bigger rocks which eventually get big enough to have a significant gravity field around it.
Then they really start to grow, attracting ever larger volumes of rocks and water ice so they end up having immense stores of ice inside them. Now when a giant planet like Jupiter is encountered, the smaller moons and comets and asteroids have chaotic orbital effects which slings some of them clean out of the solar system but some get slung INSIDE Jupiter to collide with the sun and the inner planets.
The thing is, that doesn't happen by the onsies and twosies, it happens by the thousands and some of those objects are very large and have a LOT of ice inside.
Crashing into Earth will leave some of that water left over when the hit subsides and more and more of these things hitting will leave more and more water on Earth. The same thing happened to the Moon, Mars, Venus, and Mercury but all those planets and moons had their own problems keeping the water.
Venus had the unfortunate runaway greenhouse effect that left that planet with an atmosphere with the pressure of the inside of a nitrogen bottle, 1500 PSI and a temperature of 900 degrees F and mostly carbon dioxide and sulfuric acid vapor.
Not much chance for liquid water there.
And of course Mercury and the Moon, being fairly similar in terms of atmosphere, could not retain much of its incoming water but there still is some on both worlds hidden out in craters that never receive radiation from the sun, but not oceans full.
And then there is Mars. It got the same input of water as did Earth, but of course somewhat less because its gravity is lower than Earth's and therefore would have attracted somewhat less of the asteroids and comets flying about in the early history of the solar system.
But it did get a lot of water nonetheless and there was early on an atmosphere and temperature to allow liquid water so there were seas and lakes and so forth on Mars back then and maybe even life, which we should prove one way or another in the next 40 years or so.
The problem with Mars was it had not much in the way of a magnetic shield since its core froze pretty early on in its history. A liquid core in totally necessary to have a planetary wide magnetic shield.
Mars clearly shows what happens when you DON'T have such a shield.
The solar wind coming from the sun simply skims off the top of the atmosphere 24/7 for millions of years till there is practically nothing left, its atmosphere is about 1 percent of Earth's now, not enough to allow much in the way of liquid water.
It is said there could be liquid water for short periods of time as brine and it is thought there is a lot of water underground on mars but the surface water all evaporated away.
Recent analysis from Curiosity driving right now on mars is showing the dirt there and rocks to be about 2 percent water, a surprising discovery which will bode well for future colonists since all you have to do is heat up the rock to a few hundred degrees and catch the steam and you have all the water you need for a colony.
You probably don't believe a word of what I just wrote but astronomers see protostars in all stages of development and can see clearly the formation from dust cloud to planets.
We strongly feel this is exactly how the sun itself formed, from a cloud of an exploding nova, which we also have copious photo's of in nearby space in our galaxy, collapsing in places where the density is enough to cause a solar system wide collapse of the stuff from the death of stars which includes iron, aluminum, silicon, gold, and so forth, carbon, oxygen, hydrogen, and that can form many minerals while still in space and of course, water.
So the cloud starts spinning and the collapse continues till the inner core becomes dense enough to start up the fusion process and now it is a star.
The resulting radiation blows away the inner volume which leaves most of that matter out further near Jupiter, half a billion miles from the sun and so forth, but with enough material left over to have formed our inner planets.
That is the current thinking of scientists around the globe and of course you poo poo all that but all you have to do is look at the astrophoto's of protostars to see the same thing happening all over our galaxy. Proof enough for us.
Look at these images:
And this, where the dark spots are where new stars form directly from the explosion of large stars, which is what the cloud in this photo is: