Posts Tagged ‘earth’

Everybody’s favourite planet (apart from probably Mercury) – Earth!

March 23, 2011

Earth… perhaps the most unknown planet in our solar system. So what is there to know about this obscure planet?

What makes Earth special is that it is in something called the ‘Goldilocks zone’. This means that it is just the right distance from the sun to be neither too hot nor too cold, allowing it to support liquid water. This is essential for life, and is partially why Earth is the only planet we know of to date to support life.

The element most present in the Earth’s composition, by mass is in fact Iron, making up 34.6% of Earth, followed by Oxygen and then Silicon.

Earth is the only planet in our solar system not named after Greek or Roman mythology- instead Earth’s name has its roots in Old English and Germanic dialects.

Most of the mass of the earth is in the viscous liquid mantle, followed by the semi-fluid outer core and solid iron inner core. The crust only makes up a very small portion of the Earth as a whole.

Earth differs from other terrestrial planets in the solar system in the way its crust floats as plates on top of the mantle.

The Earth’s crust is mainly made up of quartz.

The Earth’s core can reach temperatures of 7500K in the centre, exceeding those on the surface of the sun.

The Earth is denser than any other major body in the solar system.

In fairly short periods of time (only about 500000000 years or so) the Earth’s surface will actually be completely destroyed and recreated, so no traces of the early earth are left on the surface today. 

Without life on Earth Oxygen probably wouldn’t exist, due to its reactivity. As it is it makes up about 21% of the Earth’s atmosphere, Nitrogen being the most abundant gas at 77%

And, just for you Ieuan-

            Socialists live on Earth.

Everybody’s favourite planet (apart from probably Earth) – Mercury!

March 19, 2011

Today I’m talking about Mercury. (Can you see a running theme? – crazy!)
The closest planet to the sun, Mercury basically resembles our own moon in that it is mainly cratered with regions of smooth plains has no natural satellites and no atmosphere. Being so close to The Sun Mercury only takes 87.969 earth days to orbit it fully unlike Earths 365.3, it is also the smallest planet in the solar system and has the smallest axial tilt.

We don’t really know that much about Mercury as you can only see an illuminated crescent when looking through a telescope, however we do know that it has a core of iron which generates a magnetic field about 1% as strong as the earths. This large iron core makes the planet incredibly dense. The surface temperature of Mercury varies from -183 °C, at the bottom of its deepest craters near the poles and 427°C at its subsolar point, its mean temperature being 169.35 °C. So all in all a pretty inhospitable planet! Still at least its named after the roman god of trade… And he had wings on his hat!

The Sun.

March 16, 2011
So, we’re all living on one of many planets, in one of many solar systems, in one of many galaxies, in the one universe that we’re aware of.
So we’re pretty insignificant. But hey, luckily we, as a species, have the ability to discover and learn about the great world around us.
Let’s start with something familiar…
‘The Sun’ is the name we have given to the only star in our solar system. It’s a big ball of really hot gas. We can feel its heat from Earth and we’re between 91 and 94.5 million miles away depending on our position of orbit.
The sun, like all other stars gets its energy from burning its gases by nuclear fusion. It’s around 14 000 000°C at the center (where the fusion of atoms happens), but only 6000°at the surface. Most stars are made up almost entirely of two main gases: hydrogen and helium.
Our Sun was born from a cloud of gas around 5 000 million years ago. It is made up of different layers of gas; the surface is called the photosphere. Huge flames of hot gas occasionally explode from here. They’re called Solar Flares and Prominences.
I’ll just throw this out there:
Our Sun has a 1 393 000 kilometer diameter. It rotates once every 27 Earth days.
It has 8 planets orbiting it (Poor Pluto :/)
earth sun comparison
As with all stars our Sun will eventually die, but luckily for us, we’ve got about another 5 000 million years until this occurs. When it does, it will have used all its hydrogen and helium will become its main fuel. It’ll expand to around 100 times larger and 1000 times brighter. It will then be a Red Giant. It will then shrink to a white dwarf star, only the size of the Earth.