Spaceship Earth 'Life support'

That's a line that is in almost every space movie at some point, Usually when there's been a problem that the crew of the ship has just fixed and life is about to return to 'normal' as it were.

It's something that we probably take for granted, that we have air to breathe, water to drink and food to eat, but things weren't always this way on Earth, in fact, when the earth first came into being, it wasn't a very nice place to be, life could not exist on the early earth, yet it came into being, how can that be?

When you think about how much people want to tell you that science and faith disagree, you'd probably agree that I'm making a BOLD statement, but then read the next line of the Genesis account.

But the Earth was formless and void, and a great darkness hovered over the face of the deep, and the Spirit of God was hovering over the face of the waters. (Genesis chapter 1 verse 2)

Did you know that the present theories of how the earth was formed said that about five billion years after the initial explosion that was the 'big bang' there would have been another one that began the forming of our Galaxy, and five billion years into that the gases of Hydrogen and Helium in our area of the Galaxy reached critical mass and exploded throwing out the heavier elements into orbit that would later form into the planets of our solar system, our sun was born in that inferno, and so was our planet, in fact the very atoms and molecules that make up our bodies were constructed in that moment!

So the two aren't so very different!

Literally billions of rocks were created in that explosion. Not just the eight planets we know of, but all the asteroids, comets, meteors, gases and everything we know was created in the nuclear reaction that took place right there and then.

Scientists estimate that our solar system has not just eight planets and a number of 'dwarf planets' (we'll get to what they are in another hub) moons, comets and the like, but around four hundred billion rocks that we know of make up our solar system! and that's just our estimates, we haven't actually seen the edge of our solar system, it's too far out.

Yet there's only one place where life is known to exist, how is that?

Earth is just far enough away from our sun that water doesn't boil away on our surface.

On Venus, it never gets that cool. Venus is our nearest neighbour and is only thirty million miles closer to our sun, but the temperatures there is around two hundred degrees centigrade (about four hundred and twenty Fahrenheit).

Part of the reason is that Venus' atmosphere is 95% Carbon dioxide, a gas that traps heat in, and doesn't allow heat to escape, allowing the excess heat to escape is a vital 'safety valve' of the system

Earth has less than 500 molecules per million of carbon dioxide, but that is rising with the use of fossil fuels (even the gas in your tank is making it rise) but even the carbon dioxide that's there is important for keeping the planet warm enough.

Our atmosphere is 78% nitrogen, 21% Oxygen and the rest made up of gases like Argon (0.98%) and the rest of various other gases, all of which are essential for life, but most would kill us if we had only them to deal with.

Mars Is the opposite of Venus, it's fifty million miles further out from the sun than we are, but the temperatures are mostly below zero meaning that the little water that is there is almost permanently frozen, Mars did have water at one stage, but being only 80% the size of Earth it's gravity wasn't strong enough to hold the water, it also has an atmosphere that's only 1% that of earth (for the same reason weak gravity)

Back to Earth and Oxygen

Oxygen in the wrong form or wrong dose would kill us within minutes, yet we need it to survive! The only gas in our atmosphere that wouldn't kill us for inhaling would be nitrogen, but our bodies are geared, in fact almost every life form is geared to use Oxygen as it's fuel for life, how did we get this mix in the first place!

Okay, for some of you I probably am stretching things a bit, but hear me out.

What are comets mostly made up of?

What are Saturn's rings mostly made up of?

Neptune and Uranus are both known as ...Giants what word precedes it?

What covers Pluto's surface?

The answer to all of those is one thing ICE

ICE but not just your common garden bit that's in the freezer, this stuff is so cold it's like a solid rock!

A mountain of Ice estimated to be as tall as Mount Blanc on the surface of Pluto, comets with ice so cold that as they streak towards our sun and heat up they leave a tail or water vapour, so much so that it's actually where scientists now think the water on the surface of our planet originally came from!

According to their timetable, the first water arrived on earth like this around three billion years ago, and with it the first Oxygen.

And the first building blocks of the life support system had arrived.

Mars Had water, but being smaller than earth, it seems not to have been able to hold onto that water, though recently some has been found, and it's thought that during the Martian summer the Ice in the 'permafrost' on the surface turns into a kind of sludge that we could call water.

Venus is far too hot for water to stay.

Mercury Believe it or not there are places on the surface of Mercury (the nearest planet to our sun) that are thought might have ice all year round at the poles where there are craters that stay in the shade all the time, though outside the shade it's a steamy one hundred and sixty degrees centigrade (Three hundred Fahrenheit)

The only other place that might have liquid water is Europa One of the moons of Jupiter that has an ice-covered surface but might have liquid water underneath at it's thought that it's close enough to Jupiter for the massive planet to cause volcanic eruptions.

Yet Earth has water, and enough to allow life to develop!

And we don't really know how it all began!

That's the question we have now, sorry but I can't help wondering with this as the hub seems to be taking its own direction, but I want to go with it and see where we end up!

See to create the Oxygen we need plankton, simple-celled creatures (I'm not sure if they're single-celled) that live in the sea, and all they need is sunlight and water to produce the element in the gaseous form we all need to survive.

It's thought that the very first of these might have been sulphur based but as none exist today we'll never really know!

But earth's life support systems rely on these creatures, they even actually 'live' inside other plants and produce the carbohydrates that those plants need for them!

By the way, this was only discovered in the last few years, before that we thought that the plants themselves produced the Oxygen, but no, it's the plankton or 'cyanobacteria' as science calls them.

Put simply it's the fact that Earth has liquid water, heat to keep the water liquid, but not so much that the water boils away, and even has a means of regulating the temperature (rain and evaporation).

Along with that it also has tiny creatures that produce the very gas that sustains all other life on the planet, and they work with other plants to help them produce the carbohydrates needed for their growth and life, all of which is geared for higher life forms to develop and live.

Putting things simply, Earth is purpose-built for life

And it has shields to protect that life!

Hope you enjoyed this hub and the little quiz at the end.

Anyway, this is just some of how wonderful the place the human race calls home really is, in the next one we're probably going to be going into some of the problems that we face as a species and what we can do about them, it's going to be an interesting ride here on 'Spaceship Earth'

Hope you enjoyed the ride so far'

Blessings

Lawrence