The coldest, driest, and iciest of Earth's continents, Antarctica is home to some of the most important and ambitious science projects on the planet.

Here, at the West Antarctic Ice Sheet Divide, Kendrick Taylor and his team of glaciologists drill into ancient ice to pull up ice cores, which trap bubbles of the atmosphere from the time that ice fell as snow. In order to predict future changes in climate, scientists verify and refine their models against paleoclimate data from the ice cores Taylor and others pull up. The researchers are working to construct a record of carbon dioxide levels in the atmosphere over the last 100,000 years.

Nature's stained-glass windows are buried in Antarctic ice: Polarizing filters reveal the orientation of crystal grains in thin sections of ice pulled up at the West Antarctic Ice Sheet Divide. The transparent shapes, which appear black in low light, are crystals with an orientation that's perpendicular to the ice slice, and each color corresponds to a different angle relative to the plane of the ice section.

Studying individual ice crystals can yield all sorts of information. For example, thicker ice crystals form in summer, and thinner crystals form in winter, so researchers can look at the size of the crystals--and of the air bubbles in their gaps--to determine when that ice fell as snow.

A snow pit shows off the season-by-season stratigraphy at the West Antarctic Ice Sheet Divide. Behind this wall of snow is open air, which allows the sun to peek through the various layers of snow. The uppermost dimmer layer is snow from last winter, the bright layer in the center is last summer, and the dimmer layer at bottom is the winter before that.

The ice cores pulled up at WAIS will be dated by counting back these seasonal layers as if they were tree rings.

Cape Royds, which is part of Ross Island in Antarctica's Ross Sea, is home to the southernmost penguin colony in the world. Ad??lie penguins only began to thrive here recently, a consequence of global climate change breaking up sea ice and offering better access to the cape. While the penguins primarily live on sea ice, they seek out ice-free land to breed and to incubate their eggs.

Scientists studying Antarctic penguin populations have recently noticed a trend in their numbers: While Ross Sea colonies like this one have grown, colonies on the Antarctic peninsula have shrunk. It is unknown whether the shift in distribution is due to migration or a simple balance of more die-offs in one region and more births in the other, but in either case, this colony's growth spurt seems to come at the expense of the peninsular colonies.

In the case of these Adelie penguins, it seems that the climate shifts that have helped the Ross Island colony thrive are harming colonies on the Antarctic peninsula; since warmer air can hold more moisture, snowfall has increased on the peninsula, limiting the penguins' ice-free breeding grounds.

At the South Pole, astrophysicists drill 1.5 miles into the ice to hunt for neutrinos, the subatomic particles that are a byproduct of violent cosmic events. Because neutrinos are tiny and electrically neutral, they can travel across the universe without interference, bringing with them information about their distant astrophysical sources.

Researchers from the IceCube project will place a string of Digital Optical Modules into this hole, which can detect the faint signal produced on the rare occasion when a neutrino collides directly with the nucleus of an atom in a molecule of ice.

Strings of Digital Optical Modules (DOMs) are lowered into the deep holes, surveying the ice for neutrinos. When a neutrino collides with an atomic nucleus, a new particle called a muon is produced, which emits a faint blue glow in the transparent ice that the DOMs can detect.

A string of DOMs is essentially a telescope pointed at the ground: The DOMs will look for neutrinos that originated in the northern sky, passed through the Earth without resistance, and lodged themselves in the South Pole's ice.

One of the few perpetually ice-free regions in Antarctica, the McMurdo Dry Valleys are home to some of the coldest and driest exposed land on Earth. These properties make the Dry Valleys so unusual that they more closely resemble Mars than they do most of Earth, and therefore make a great research station for planetary scientists who can't yet buy a ticket to Mars.

According to Joseph Levy, a geologist at Portland State University pictured here in green, Antarctica's Taylor Valley approximates the surface conditions on Mars roughly three billion years ago.

At the Amundsen-Scott South Pole Station, meteorologist Timothy Markle prepares to launch a weather balloon. The balloons must first be heated to regain their elasticity, which is robbed from them in storage by the -4 degrees Fahrenheit surface temperatures in the southern hemisphere's summer.

This weather balloon will mostly measure temperature, air pressure, and wind speed, but others sample the air for the concentration of various gases like carbon dioxide and oxygen. The air sampled from the South Pole's clean air sector (a zone where air traffic, land vehicles, and even foot traffic is strictly limited) is touted as the cleanest air on Earth.

The South Pole Telescope, which began scientific observations in 2007, surveys the sky for cosmic microwave background radiation, the "afterglow" of the Big Bang. Free electrons in galaxy clusters distort the radiation, casting "shadows" in the background radiation that astrophysicists have already used to identify previously unknown galaxy clusters.

The South Pole is the best place on the planet for these observations, as it's on a plateau that's almost 2 miles high, and the high, cold air contains very little radiation-distorting water vapor.