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Antartica is a cold and isolated place, but intrepid scientists have found ways to make use of its environment, and turn it into one of the ideal places to study our skies.

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What do you think of when you think of Antarctica?  Ice?  Penguins?  David Attenborough talking about ice and penguins?  But  Antarctica isn't just a penguin paradise, it's also a haven for astronomy and for weirdly, some of the same reasons.  The cold keeps the air crystal clear a lot of the time and reduces thermal interference which is exactly what many telescopes need.  

Antarctica's isolation also means the skies are some of the darkest on Earth and its position at the South Pole means that there can be months of continuous darkness, exactly what astronomers want if they're looking at something faint.  Astronomers and physicists have even figured out a way of using the ice itself as a giant observatory, and as a window into the solar system's ancient history.  The only downside of astronomy in Antarctica is that like, it's Antarctica.  But hardy scientists and hardy instruments mean that that's not as much of a barrier as you might think, and to prove it, here are five reasons why Antarctica is the place to be when you want to study space.

 1: IceCube (1:25)

If you've ever thought that astronomers spend too much time looking up, well, the IceCube Neutrino Observatory is for you.  They do astronomy and physics by staring down into ice.  Near the South Pole is pretty much the only place on Earth where you will find huge slow moving expanses of ice that don't melt.  Not completely, that is.  IceCube stares into a cubic kilometer of ice near the South Pole in order to study neutrinos, which are fast moving, elusive, incredibly tiny sub-atomic particles that we mostly understand except for a bunch of stuff that we're still trying to learn about them, and neutrinos will pass through just about anything without bumping into them, like a trillion go through your nose every second, which makes them incredibly difficult to study in a laboratory.  

 (02:00) to (04:00)

Seeing the unlucky few that happen to bump into something generally requires building giant detectors, but in 1999, a team of scientists pointed out that they could just use the Antarctic ice sheet as one giant neutrino target, which led to the development of the IceCube project.  See, neutrino detectors don't need to be made of anything special, but they do need to be pretty big and pretty see-through, like a giant ice sheet.

Most neutrinos will actually pass right through the ice, but every once in a while, one crashes into a water molecule and that collision sets off a chain reaction that eventually releases light that IceCube's detectors can see, but the light doesn't just tell IceCube scientists that there was a neutrino there.  Its direction, intensity, and other properties can show scientists a lot about the neutrino that caused it and where that neutrino came from.

Lots of things in the universe make neutrinos, but far fewer make neutrinos with as much energy as IceCube's detectors are tuned to notice, and those detectors see a couple hundred neutrinos a day, and scientists have used data about those neutrinos to study some pretty extreme environments outside of our planet like spinning neutron stars and the violent centers of galaxies, but that's not all.

Many scientists think dark matter, which has mass but doesn't give off light, might be made of tiny particles that act somewhat like neutrinos.  IceCube is an ideal observatory to search for evidence of those hypothesized particles.  So far, though, they haven't seen anything, but they're still looking.  After all, they've got the ice for it.

 2: BICEP (3:59)

There are, of course, also more traditional telescopes in Antarctica, including a few that study microwaves, the type of thing that you might use in your kitchen to heat up a burrito.  

 (04:00) to (06:00)

Microwaves have longer wavelengths than visible light and they're used for heating up food because water absorbs microwaves really well, turning them into heat.  In fact, water is so good at absorbing microwaves that most of the microwave radiation Earth receives from space never gets to the ground.  It's absorbed by water in the atmosphere, but that's why scientists looked at Antarctica when they were planning out the Background Imaging of Cosmic Extragalactic Polarization experiment, or BICEP for short.

Antarctica is the largest desert on Earth.  The air there is just too cold to hold much water, so microwaves pass right through it, but BICEP doesn't just study any microwaves.  Along with the nearby Keck array, it studies the cosmic microwave background or CMB, the oldest light in the universe.  

The CMB is a sort of fingerprint of the Big Bang that lets scientists examine the universe when it was only a couple hundred thousand years old by revealing how matter was distributed all the way back then.  Astronomers can test the Big Bang model by testing its predictions of how the universe evolved and where matter should be against the blobby arrangements of matter that we see in the CMB.  It's one of the best tools for understanding the universe and Antarctica is one of the few places on Earth with a clear view, and BICEP's already made some great contributions to our understanding of the cosmos.

The CMB shows us evidence of where matter was in the early universe and those measurements almost exactly match up with what we would expect from our models, which helps us confirm that our understanding of all this is on the right track.  Best of all, it also helped astronomers shed light on some things they don't really understand yet, which means more science to do.  

 3: South Pole Telescope (5:58)

The name of the South Pole telescope is pretty spot on.  

 (06:00) to (08:00)

It's at the South Pole, it's also a telescope.  SPT studies microwaves just like BICEP, and while it's also been used to study the CMB, a lot of its time has been spent looking at what happened to the CMB's light as those microwaves move through space, because Antarctica isn't just dry, it's also high.  

SPT has less light distorting atmosphere above it than many other places on Earth, because it's sitting on top of almost three kilometers of ice.  On top of that, Antarctica is also dark, at least in the winter.  The Sun doesn't rise for months, so the sky stays dark and instruments stay at a pretty constant temperature, so SPT and other telescopes can just keep looking out into the universe all winter with almost no interruption.

Recently, it's been used to study galaxy clusters, some of the biggest structures in the universe.  Gas and dust around these clusters distort the light of the cosmic microwave background, so SPT can understand the amount of mass in the clusters by looking at how much the light is distorted, and by understanding clusters, astronomers can understand the kinds of influences that formed them, and that includes stuff that we don't fully understand like dark matter and dark energy.

Dark matter pulls things in the universe together without emitting its own light and dark energy pushes things apart.  These competing forces both influence the formation of galaxy clusters, so SPT's measurements can help astronomers inch their way toward understanding the behavior of the universe's most mysterious features, and speaking of mysterious pieces of the universe, SPT also participated in a global network known as the Event Horizon Telescope.

This project famously combined images from lots of telescopes around the world to take the first picture ever of the hot gas surrounding a supermassive black hole.  The bigger the distance between the telescopes, the better the Event Horizon picture would be, and it's harder to get farther from most places on Earth than the South Pole, meaning Antarctica's remoteness was actually an advantage.

 (08:00) to (10:00)

Antarctica is constantly surrounded by some of the strongest circular ocean currents and winds on Earth.  They make it hard to get to Antarctica in the first place and they make it hard to leave whether by ship or by plane, and that might sound like a bad thing, but NASA has found a way to use Antarctica's powers for good.  

 4: NASA's balloons (8:32)

They've launched a series of football field-sized balloons that get carried around the continent by those strong predictable winds, giving us observatories that just float around kilometers off the ground.  With so much less air between them and outer space, these flying instruments can see things that are much harder to find from the ground, things like cosmic rays, charged particles like protons that fly through space at nearly the speed of light.

Cosmic rays come from all over the place in the universe, but different kinds of objects make different kinds of rays, so by studying the rays, astronomers can learn about the objects themselves.  The Baccus mission was able to use cosmic rays to study how abundant elements like boron and carbon are throughout the universe.  CREAM and ANITA, two other high-altitude balloons, have used cosmic rays from dying stars to understand supernovas, the explosions made by dying stars.

Other Antarctic balloons have studied Earth's magnetic field and still others have studied the magnetic fields of stars.  All these balloons don't just take advantage of Antarctica's plentiful winds.  Daytime lasts for months during the summer, so you don't have to worry about solar powered instruments going dead at night and you don't have to worry about balloons cooling down as the temperature drops at night because there is no night, all thanks to Antarctica's unbeatable location as an island at the South Pole.  

 (10:00) to (12:00)

 5: ANSMET(10:00)

Now let's come full circle to another group of Antarctic astronomers who look down instead of up: those working with the Antarctic Search for Meteorites, which is about as well named as the South Pole Telescope.  In the 70s, scientists started realizing that Antarctica is so completely covered in ice that there are huge stretches where there are hardly any natural rocks, and if you do find a rock, there's a better than usual chance that it is not from Earth.  Over the decades, the Antarctic Search for Meteorites or ANSMET and other teams have found about 50,000 meteorites down there, and it's not just stuff that fell recently.

The ice sheet acts like a conveyor belt as it flows, carrying old meteorites along for the ride until it crunches up against something like a mountain range.  Near the mountain range, the ice bunches up, squeezing trapped ancient rocks toward the surface.  Most of the meteorites scientists find there are from when the most common types of asteroids crashed into other asteroids with debris from the collision, eventually finding its way to Earth.  These ordinary chondrites as they're known reveal the conditions of the early solar system, when the asteroids first formed, but not all meteorites are ordinary chondrites and some of the others come with very specific stories.

Based on what it's made out of, scientists can tell which specific object in the solar system a meteorite came from.  Lots of meteorites come from Vesta, one of the solar system's largest asteroids, but lots come from other places, like Mars, and in the 90s, a team studying a Martian meteorite known as ALH84001 made an announcement that is still controversial more than 20 years later.

They thought they saw signs of microscopic fossils, traces they claim could only have been left behind by ancient Martian bacteria.  Most scientists don't agree with those claims, but everyone does agree that without Antarctica's isolated ice sheets, this and thousands of other meteorites, would never have been found, and without them, we would have a much worse understanding of our place in our solar system and in our universe, so Antarctica might be cold, remote, dry, and icy and dark for half the year, but that's not enough to stop our intrepid astronomers, and whether they're looking up into space or down into the ice, they're teaching us more about our place in the universe than they ever could if we wrote off Antarctica as only being good for penguins.

 (12:00) to (13:30)

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