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

99% sure this is all computer-generated, but it’s so pretty. It’s a clip as though you are flying around a star-forming nebula, with colors of the gas clouds generated by the heat of newly-formed stars within. Outside the nebula, tiny points of light, individual solar systems, pass by you like snowflakes.

Original caption: 

“As the days shorten and the darkness progressively eats away the light, an amazing transformation happens in the northern hemisphere skies. A lot of astronomers and stargazers prefer summertime to look up at the stars, probably because conditions are better and the brightest part of our own galaxy, the milky way is more visible, even with the naked eye. Although fainter, the ‘winter’ part of the milky way and the rest of the winter sky harbor countless unsuspected gems, if one knows how to find and capture them! 

In the late Fall, you can still get a glimpse at the bright core of our galaxy sink down under the horizon just after sunset, along with its dark hydrogen gas lanes, Lagoon and trifid nebulae, and Saturn. Later, you can catch Scutum (shield constellation) and its dark nebulosity set in the south west/west. In the movie, this part is visible in many scenes but my favorite one is by far as it sets on La Palma shores behind a thunderstorm accompanied by red sprites, airglow and zodiacal lights.

Then, take a peek at one of my favorite areas of the winter sky: the Swan constellation. I presented it to you (also on the cover), so that you can see it from different perspectives, but the best is probably at a narrower angle to show the beautiful magenta colors of the H-alpha emission nebulae (North-American, Pelican, Sadr region or IC 1396). I also included a scene where the ‘Summer Triangle’ of Cygnus (formed by Deneb, Sadr, Delta Cygni, and Gienah) is photobombed by an overhead aurora borealis. Continuing along the winter milky way, I included a shot of the Heart and Soul nebula. Rising on the other side of the hemisphere, we are now looking at the outer edge of our galaxy, where very little light comes from fewer stars, nebulae and dark clouds (in comparison to the core!). I wanted to show you a very novel scene combining the hot Pleiades stars reflecting their blue light onto passing gasses and the California nebula glowing blood red! The next area I want to emphasize is winter’s most emblematic: Orion. I wanted to maximize the different colors and brightness this constellation has to offer while shooting it in a series of single shots: the orange of Betelgeuse and the blue of Rigel, the gigantic red-glowing Barnard’s loop, the inevitable shell-like Orion nebula along with the running man nebula, the horse-head nebula, the flame nebula, Lambda Orionis nebula… Further away from the winter milky way doesn’t mean dull at all, au contraire! Look at the magnificent Andromeda galaxy (M31), the size of 6 full moons- rise above the tree line! What about the iconic Big Dipper being photobombed by some pillars of Icelandic and Canadian aurora borealis? What about these iridescent marbles at the very start of the video? Those are twinkling Sirius, Capella (bottom left) and Vega (upper right) emphasized by the real-time out-of-focus setting to reveal the hypnotic shift in light and colors of these twinkling stars created by our own atmosphere! You will probably miss a lot of night sky events if you only watch the video once! Don’t blink, you might miss a lot of meteors (Perseids, Orionids, Draconids, Leonids…), iridium flares, low-orbit satellites, red sprites. What about those satellites that seem to ‘follow’ each other in some deep-sky scenes? Those are geosynchronous satellites normally hovering over a fixed point of the Earth, but the motion of the star tracker allows them to move whereas the sky is now immobile. I am sure professionals and amateurs will spot many more features, all you have to do is sit back and gaze! 

The goal of this series of astro-lapses ‘Galaxies’ and especially this second opus was a way for me to push the limits of single astrophotography. However beautiful and numerous they are, wide-angle shots of the milky way moving against a foreground became less interesting to me as I got to shoot more and more astro-timelapses. I became more interested in exploring the possibilities that modern lenses, sensors and techniques could give, so I started using medium-format and astromodfication to take advantage of a wider light spectrum and show the red colors of H-alpha emission nebulae that are so ubiquitous in the winter part of the sky. I also wanted to improve the quality of the shots, so I used a square light pollution filter for shots at more than 50mm (Lonely Speck’s Pure Night LP filter), and a star tracker for some of the scenes to increase sharpness and details (Vixen Polarie). It was very important for me to prove that deep-sky time-lapses can be very interesting and successful, whether they hold a foreground or not, because so many things can be happening the sky (airglow, meteors, satellites, haze giving a temporary glow to the stars…). All shots have been recorded over the past year and in different countries (France, Switzerland, Spain, Iceland, Denmark and Canada). I will gladly give more details upon request. Thanks a lot for watching!”

Original caption:

I cannot tell you how this video was made, whether this is all computer generated or whether there is some Hubble telescope image on which some of this is based...but basically here is a chance to float around through 10 minutes of whispy nebular clouds and stars forming out in space.

Milky way and Large Magellanic Cloud panorama over Mount Kilimanjaro, Tanzania

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