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spaceplasma:

xysciences:

A gif representing nuclear fusion and how it creates energy. 
[Click for more interesting science facts and gifs]

For those who don’t understand the GIF. It illustrates the Deuterium-Tritium fusion; a deuterium and tritium combine to form a helium-4. Most of the energy released is in the form of the high-energy neutron.
Nuclear fusion has the potential to generate power without the radioactive waste of nuclear fission (energy from splitting heavy atoms  into smaller atoms), but that depends on which atoms you decide to fuse. Hydrogen has three naturally occurring isotopes, sometimes denoted ¹H, ²H, and ³H. Deuterium (²H) - Tritium (³H) fusion (pictured above) appears to be the best and most effective way to produce energy. Atoms that have the same number of protons, but different numbers of neutrons are called isotopes (adding a proton makes a new element, but adding a neutron makes an isotope of the same atom). 
The three most stable isotopes of hydrogen: protium (no neutrons, just one proton, hence the name), deuterium (deuterium comes from the Greek word deuteros, which means “second”, this is in reference two the two particles, a proton and a neutron), and tritium (the name of this comes from the Greek word “tritos” meaning “third”, because guess what, it contains one proton and two neutrons). Here’s a diagram
Deuterium is abundant, it can be extracted from seawater, but tritium is a  radioactive isotope and must be either derived(bred) from lithium or obtained in the operation of the deuterium cycle. Tritium is also produced naturally in the upper atmosphere when cosmic rays strike nitrogen molecules in the air, but that’s extremely rare. It’s also a by product in reactors producing electricity (Fukushima Daiichi Nuclear Power Plant). Tritium is a low energy beta emitter (unable to penetrate the outer dead layer of human skin), it has a relatively long half life and short biological half life. It is not dangerous externally, however emissions from inhaled or ingested beta particle emitters pose a significant health risk.
During fusion (energy from combining light elements to form heavier ones), two atomic nuclei of the hydrogen isotopes deuterium and tritium must be brought so close together that they fuse in spite of the strongly repulsive electrostatic forces between the positively charged nuclei. So, in order to accomplish nuclear fusion, the two nuclei must first overcome the electric repulsion (coulomb barrier ) to get close enough for the attractive nuclear strong force (force that binds protons and neutrons together in atomic nuclei) to take over to fuse the particles. The D-T reaction is the easiest to bring about, it has the lowest energy requirement compared to energy release. The reaction products are helium-4 (the helium isotope) – also called the alpha particle, which carries 1/5 (3.5 MeV) of the total fusion energy in the form of kinetic energy, and a neutron, which carries 4/5 (14.1 MeV). Don’t be alarmed by the alpha particle, the particles are not dangerous in themselves, it is only because of the high speeds at which they are ejected from the nuclei that make them dangerous, but unlike beta or gamma radiation, they are stopped by a piece of paper.
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spaceplasma:

The Voyager Within
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comaniddy:

That creature you see right there is the teeny-tiny Water Bear. They are one of Nature’s toughest creatures.
I found this little tardigrade on tree moss. And in an upcoming SciTune, the folks from the BioBus and I will teach you how to find them!
comaniddy:

That creature you see right there is the teeny-tiny Water Bear. They are one of Nature’s toughest creatures.
I found this little tardigrade on tree moss. And in an upcoming SciTune, the folks from the BioBus and I will teach you how to find them!
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kqedscience:

The Last Summer ‘Supermoon’ Of 2014 Is Also A Harvest Moon
“Skywatchers, you’re in for a treat. Tonight’s “supermoon” is a pretty special one.
When the moon turns full on Monday, Sept. 8 at 9:38 p.m. EDT, it not only will become the last supermoon of the summer, but also this year’s Harvest Moon — which is a full moon that occurs closest to the autumnal equinox.”
Learn more from the huffingtonpost.
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ri-science:

A cloud chamber and the birth of helium atoms.
The tracks here show the natural radiation in the atmosphere around us. Thicker tracks are big heavy alpha particles, whispy ones are beta particles, but they all work in the same way.
The atmosphere in the chamber contains a lot of alcohol vapour. When charged particles fire through the atmosphere they cause little droplets to form, and these are the clouds you can see.
This is similar to how a track forms behind an aeroplane, where the exhaust can help the droplets of moisture form together into a cloud.
When you then add an Americium pole into the chamber, the alpha particles emitted (with their two protons and two neutrons) grab electrons and form Helium atoms. 
Watch the full video with Dr Peter Wothers on YouTube.
ri-science:

A cloud chamber and the birth of helium atoms.
The tracks here show the natural radiation in the atmosphere around us. Thicker tracks are big heavy alpha particles, whispy ones are beta particles, but they all work in the same way.
The atmosphere in the chamber contains a lot of alcohol vapour. When charged particles fire through the atmosphere they cause little droplets to form, and these are the clouds you can see.
This is similar to how a track forms behind an aeroplane, where the exhaust can help the droplets of moisture form together into a cloud.
When you then add an Americium pole into the chamber, the alpha particles emitted (with their two protons and two neutrons) grab electrons and form Helium atoms. 
Watch the full video with Dr Peter Wothers on YouTube.
ri-science:

A cloud chamber and the birth of helium atoms.
The tracks here show the natural radiation in the atmosphere around us. Thicker tracks are big heavy alpha particles, whispy ones are beta particles, but they all work in the same way.
The atmosphere in the chamber contains a lot of alcohol vapour. When charged particles fire through the atmosphere they cause little droplets to form, and these are the clouds you can see.
This is similar to how a track forms behind an aeroplane, where the exhaust can help the droplets of moisture form together into a cloud.
When you then add an Americium pole into the chamber, the alpha particles emitted (with their two protons and two neutrons) grab electrons and form Helium atoms. 
Watch the full video with Dr Peter Wothers on YouTube.
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spaceplasma:

Mars Orbiters ‘Duck and Cover’ for Comet Siding Spring Encounter

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.
The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.
NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.
The European Space Agency is taking similar precautions to protect its Mars Express (MEX) orbiter.

For more information about the Mars flyby of comet Siding Spring, click here.

Credit: NASA/JPL-Caltech
spaceplasma:

Mars Orbiters ‘Duck and Cover’ for Comet Siding Spring Encounter

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.
The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.
NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.
The European Space Agency is taking similar precautions to protect its Mars Express (MEX) orbiter.

For more information about the Mars flyby of comet Siding Spring, click here.

Credit: NASA/JPL-Caltech
spaceplasma:

Mars Orbiters ‘Duck and Cover’ for Comet Siding Spring Encounter

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.
The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.
NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.
The European Space Agency is taking similar precautions to protect its Mars Express (MEX) orbiter.

For more information about the Mars flyby of comet Siding Spring, click here.

Credit: NASA/JPL-Caltech
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spaceplasma:

Time lapse of the Milky Way rising behind the South African Large Telescope (SALT)
Credit: Anthony Koeslag
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spaceplasma:

"Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring — not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive… If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds." 
— Carl Sagan - Pale Blue Dot: A Vision of the Human Future in Space (Chapter 21, p.371 )
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glitchinc:

UFOs, 2014.