The Earth Story

Let there be Light: The Making and Death of Stars

Hubble has spent nearly 30 years sending us the most amazing and dazzling photos of our Universe. Hubble has literally expanded the frontiers of human knowledge. Using it to peer deep into space and back in cosmic time, astronomers learned that galaxies formed from smaller patches of ‘stuff’ in the early universe by capturing light from newborn galaxies as it looked 13 billion years ago. The creation of this light is made from the billions of stars out there, illuminating our universe for all to see. How is this light created? How are stars made and what happens once they have used up all their energy? Lets take a brief look at the making and death of stars. First of all, some basic facts about our Sun. Our Sun is a G2 V type main sequence dwarf star (medium sized), at the center of the solar system and contains nearly 99.8% of the solar systems mass. The colour is whitey green but appears yellowish due to the scattering of blue light in the atmosphere. It is a population I star, that being rich in heavy elements, (high metallicity). The Sun was probably formed from a high proportion of material from prior supernova events (death of super massive stars way bigger than our own). Its composition is about 74% Hydrogen, 24% Helium, 0.8% Oxygen, 0.3% Carbon and 0.2% Iron. Its gravity is about 28 x the Earth’s and is about 150 million km (93 205 678.8 miles) away from Earth, or just over 8 light minutes.

Each star is different, but starts life the same way in clouds and dust called Nebulas, stellar nurseries for stars such as Orion, Eagle and Horse head to name but a few. To make a star, all you need is gravity, hydrogen and time. Gravity pulls the hydrogen gas into a swirling vortex. Gravity brings matter together and when you 'squeeze' things together in smaller spaces, they heat up, basically when you compress something you drive the temperature up. Over 100's and 1000's of years the cloud gets thicker, a large spinning vortex as big as our solar system and at the centre a large dense spinning ball where the pressure builds until large jets of gas burst out at the sides. Eventually a star ignites, throwing off any remainder gas out. With a temperature of 15 million degrees at the core, atoms of gas fuse together. BOOM! A star is born.

So, we now know how a star is created, what about what drives stars energy then? Atoms of Hydrogen smash into each other, this process is called fusion. Hydrogen atoms naturally repel one another, chemistry 101, but if they travel fast enough, really fast, they crash into each other, fusing together to make helium, heat with a small amount of pure energy. The hydrogen gas weighs slightly more than helium, loosing mass during the collision in which this mass turns into energy. Stars are huge, and to drive this you need gravity to compress the star to create nuclear fusion at its core.

What happens when the fuel runs out? Well, eventually it will run out, bigger stars use their fuel more quickly so the bigger the star the shorter its life. Gravity is in a constant battle with the stars fusion process that they balance each other out, however gravity eventually wins the battle. Our Sun is no exception, every second it burns 600million tones of its hydrogen fuel. As hydrogen gets used up, the core slows down giving gravity the edge, with less fusion pushing outward, gravity pushes inward and as fusion fights back the star begins to expand. This is called the red giant stage that will consumes all the inner rocky planets, and most likely even the Earth. This is the end of our beautiful planet Earth (although some theorists think that this process may ‘push’ Earth further out). With no hydrogen left to fuel it, the star starts to burn helium and fuses it with carbon. Blasting energy from its core to the surface, these energy waves blow away the stars outer layer and slowly it disintegrates into a “white dwarf”. A white dwarf is so dense that if a sugar cube amount were placed on Earth, it would fall right through it. Astronomers believe that in the core of a white dwarf there is solid carbon, literally a diamond in the sky!

This is the outcome of our star, but what about bigger ones? Larger stars have a much more violent ending than our G type star. The gravity of these stars is so massive that they can smash together bigger and bigger atoms. The cores of these stars are like factories, manufacturing heavier and heavier elements, which lead to the stars destruction. Gold, Silver, Nickel and other elements are all created in these stars. The next time you wear your gold chain or ring, just think, it wasn't created here on Earth, but in the death of a super massive nova. Once the star starts to make iron, this is the end. Iron absorbs the energy in a 1000th of a second, robbing it of its remaining fuel until gravity wins and the star collapses. It creates a huge explosion, a supernova and the single most violent event in the universe, spewing everything out into space. Then, the whole process of star formation begins again. If it wasn't for these massive explosions, our Sun wouldn't be here, therefore so wouldn't we.

There is only so much hydrogen in the universe and astronomers believe that eventually, the entire universe will simply run out of the star forming gas and eventually the lights will all go out. Thankfully, we will not be around to see this, nor see the death of our own middle-aged star in about 4.57 billion years. We have a long time to appreciate it and be thankful for its life giving ingredients. To be thankful that its rises, sets and rises again, because without it, it’s goodnight sweetheart smile emoticon

Carbon, Oxygen, Iron in our blood, Everything around us came from the belly of a star. We are in a 'golden age' of the universe. A good time to be here, seeing the best of all stages of the universe, filling the darkness with light. For we are all made of stardust.

~ JM

Image Credit: http://bit.ly/1FnZ8dV

More Info:

Hubble: http://hubblesite.org/

Sun Facts: http://bit.ly/1xqjsaz

NASA Solar Dynamics Observatory:http://sdo.gsfc.nasa.gov/

Space Weather: http://www.spaceweather.com/

Encyclopaedia Britannica: http://bit.ly/1CiFOPI

Stellar Evolution: http://bit.ly/1BkXinG

Why Are So Many American Barns Red?

If we start at the beginning then we need to talk about star birth. Not just any star, and not a living star; these stars (note the plural) have been dead for probably billions of years. But while they were living they did some pretty incredible things. Most importantly to our topic, they made iron.

When a star is born it's just a big ball of gas. There are some light elements floating in space that cluster together due to gravity, pulling each other in until they fuse, transforming hydrogen into the heavier element helium, for instance. These heavier elements are also floating around, but because of their weight they huddle a little closer (again due to gravity). As they do so, the temperature and the pressure inside the star continues to increase until they, too, fuse, forming an even heavier element. And the cycle continues.

This happens in all stars until a very specific threshold is reached. Stars don't create elements with more than 56 nucleons (or a total of protons and neutrons). Why? Because at this point there needs to be a net input of energy to create newer, heavier elements, energy which the sun just doesn't give. What is the most stable element with 56 nucleons? Iron. Stars produce more iron than anything else, and therefore iron is super abundant.

What on earth does all this star stuff have to do with red barn paint? Red paint is made from red ochre (Fe2O3), or anhydrous iron oxide. This is the stuff that makes the red paint red, thanks mainly to the way iron absorbs and reflects light. Because there is so much iron in the universe (and probably beyond) and therefore on earth, red ochre is extremely cheap, making the paint relatively cheap. And who wants to paint a cow barn with expensive paint?

In a delicious twist of fate, one of the more common adornments on American barns is the “barnstar”, considered a “lucky omen” similar to a horseshoe over a doorway.

Further reading: http://www.smithsonianmag.com/smart-news/barns-are-painted-red-because-of-the-physics-of-dying-stars-58185724/?no-ist

Picture credit: Dave Smith https://www.flickr.com/photos/skimerlin/

-Colter

This is a slow motion video clip from the Solar Dynamics Observatory (SDO) spacecraft - currently staring at the sun from Earth’s orbit. This wavelength is set to see gas in the sun’s Corona - the big opening you see is a coronal hole, opened up by the sun’s tangled magnetic field.

Let there be Light: The Making and Death of Stars

Hubble celebrates 25 years of sending us the most amazing and dazzling photos of our Universe. Hubble has literally expanded the frontiers of human knowledge. Using it to peer deep into space and back in cosmic time, astronomers learned that galaxies formed from smaller patches of ‘stuff’ in the early universe by capturing light from newborn galaxies as it looked 13 billion years ago. The creation of this light is made from the billions of stars out there, illuminating our universe for all to see. How is this light created? How are stars made and what happens once they have used up all their energy? Lets take a brief look at the making and death of stars.

First of all, some basic facts about our Sun. Our Sun is a G2 V type main sequence dwarf star (medium sized), at the center of the solar system and contains nearly 99.8% of the solar systems mass. The colour is whitey green but appears yellowish due to the scattering of blue light in the atmosphere. It is a population I star, that being rich in heavy elements, (high metallicity). The Sun was probably formed from a high proportion of material from prior supernova events (death of super massive stars way bigger than our own). Its composition is about 74% Hydrogen, 24% Helium, 0.8% Oxygen, 0.3% Carbon and 0.2% Iron. Its gravity is about 28 x the Earth’s and is about 150 million km (93 205 678.8 miles) away from Earth, or just over 8 light minutes.

Each star is different, but starts life the same way in clouds and dust called Nebulas, stellar nurseries for stars such as Orion, Eagle and Horse head to name but a few. To make a star, all you need is gravity, hydrogen and time. Gravity pulls the hydrogen gas into a swirling vortex. Gravity brings matter together and when you 'squeeze' things together in smaller spaces, they heat up, basically when you compress something you drive the temperature up. Over 100's and 1000's of years the cloud gets thicker, a large spinning vortex as big as our solar system and at the centre a large dense spinning ball where the pressure builds until large jets of gas burst out at the sides. Eventually a star ignites, throwing off any remainder gas out. With a temperature of 15 million degrees at the core, atoms of gas fuse together. BOOM! A star is born.

So, we now know how a star is created, what about what drives stars energy then? Atoms of Hydrogen smash into each other, this process is called fusion. Hydrogen atoms naturally repel one another, chemistry 101, but if they travel fast enough, really fast, they crash into each other, fusing together to make helium, heat with a small amount of pure energy. The hydrogen gas weighs slightly more than helium, loosing mass during the collision in which this mass turns into energy. Stars are huge, and to drive this you need gravity to compress the star to create nuclear fusion at its core.

What happens when the fuel runs out? Well, eventually it will run out, bigger stars use their fuel more quickly so the bigger the star the shorter its life. Gravity is in a constant battle with the stars fusion process that they balance each other out, however gravity eventually wins the battle. Our Sun is no exception, every second it burns 600million tones of its hydrogen fuel. As hydrogen gets used up, the core slows down giving gravity the edge, with less fusion pushing outward, gravity pushes inward and as fusion fights back the star begins to expand. This is called the red giant stage that will consumes all the inner rocky planets, and most likely even the Earth. This is the end of our beautiful planet Earth (although some theorists think that this process may ‘push’ Earth further out). With no hydrogen left to fuel it, the star starts to burn helium and fuses it with carbon. Blasting energy from its core to the surface, these energy waves blow away the stars outer layer and slowly it disintegrates into a “white dwarf”. A white dwarf is so dense that if a sugar cube amount were placed on Earth, it would fall right through it. Astronomers believe that in the core of a white dwarf there is solid carbon, literally a diamond in the sky!

This is the outcome of our star, but what about bigger ones? Larger stars have a much more violent ending than our G type star. The gravity of these stars is so massive that they can smash together bigger and bigger atoms. The cores of these stars are like factories, manufacturing heavier and heavier elements, which lead to the stars destruction. Gold, Silver, Nickel and other elements are all created in these stars. The next time you wear your gold chain or ring, just think, it wasn't created here on Earth, but in the death of a super massive nova. Once the star starts to make iron, this is the end. Iron absorbs the energy in a 1000th of a second, robbing it of its remaining fuel until gravity wins and the star collapses. It creates a huge explosion, a supernova and the single most violent event in the universe, spewing everything out into space. Then, the whole process of star formation begins again. If it wasn't for these massive explosions, our Sun wouldn't be here, therefore so wouldn't we.

There is only so much hydrogen in the universe and astronomers believe that eventually, the entire universe will simply run out of the star forming gas and eventually the lights will all go out. Thankfully, we will not be around to see this, nor see the death of our own middle-aged star in about 4.57 billion years. We have a long time to appreciate it and be thankful for its life giving ingredients. To be thankful that its rises, sets and rises again, because without it, it’s goodnight sweetheart smile emoticon

Carbon, Oxygen, Iron in our blood, Everything around us came from the belly of a star. We are in a 'golden age' of the universe. A good time to be here, seeing the best of all stages of the universe, filling the darkness with light. For we are all made of stardust.

~ JM

Image Credit: http://bit.ly/1FnZ8dV

More Info:

Hubble: http://hubblesite.org/

Sun Facts: http://bit.ly/1xqjsaz

NASA Solar Dynamics Observatory: http://sdo.gsfc.nasa.gov/

Space Weather: http://www.spaceweather.com/

Encyclopaedia Britannica: http://bit.ly/1CiFOPI

Stellar Evolution: http://bit.ly/1BkXinG

Why Are So Many American Barns Red?

If we start at the beginning then we need to talk about star birth. Not just any star, and not a living star; these stars (note the plural) have been dead for probably billions of years. But while they were living they did some pretty incredible things. Most importantly to our topic, they made iron.

When a star is born it's just a big ball of gas. There are some light elements floating in space that cluster together due to gravity, pulling each other in until they fuse, transforming hydrogen into the heavier element helium, for instance. These heavier elements are also floating around, but because of their weight they huddle a little closer (again due to gravity). As they do so, the temperature and the pressure inside the star continues to increase until they, too, fuse, forming an even heavier element. And the cycle continues.

This happens in all stars until a very specific threshold is reached. Stars don't create elements with more than 56 nucleons (or a total of protons and neutrons). Why? Because at this point there needs to be a net input of energy to create newer, heavier elements, energy which the sun just doesn't give. What is the most stable element with 56 nucleons? Iron. Stars produce more iron than anything else, and therefore iron is super abundant.

What on earth does all this star stuff have to do with red barn paint? Red paint is made from red ochre (Fe2O3), or anhydrous iron oxide. This is the stuff that makes the red paint red, thanks mainly to the way iron absorbs and reflects light. Because there is so much iron in the universe (and probably beyond) and therefore on earth, red ochre is extremely cheap, making the paint relatively cheap. And who wants to paint a cow barn with expensive paint?

In a delicious twist of fate, one of the more common adornments on American barns is the “barnstar”, considered a “lucky omen” similar to a horseshoe over a doorway.

Further reading: http://www.smithsonianmag.com/smart-news/barns-are-painted-red-because-of-the-physics-of-dying-stars-58185724/?no-ist

Picture credit: Dave Smith https://www.flickr.com/photos/skimerlin/

-Colter