DECEPTION ISLAND, Antarctica - Earth's past, present and future come together here on the northern peninsula of Antarctica, the wildest, most desolate and mysterious of its continents.

Clues to answering humanity's most basic questions are locked in this continental freezer the size of the United States and half of Canada: Where did we come from? Are we alone in the universe? What's the fate of our warming planet?

The first explorers set foot in Antarctica 194 years ago hunting 19th century riches of whale and seal oil and fur, turning tides red with blood. Since then, the fist-shaped continent has proven a treasure chest for scientists trying to determine everything from the creation of the cosmos to how high seas will rise with global warming.

"It's a window out to the universe and in time," said Kelly Falkner, polar program chief for the U.S. National Science Foundation.

For a dozen days in January, in the middle of the chilly Antarctic summer, The Associated Press followed scientists from different fields searching for alien-like creatures, hints of pollution trapped in ancient ice, leftovers from the Big Bang, biological quirks that potentially could lead to better medical treatments, and perhaps most of all, signs of unstoppable melting. The journey on a Chilean navy ship along the South Shetland islands and vulnerable Antarctic Peninsula, which juts off the continent like a broken pinky finger, logged 833 miles and allowing the AP team a firsthand look at part of this vital continent.

Antarctica conjures up images of quiet mountains and white plateaus, but the coldest, driest and remotest continent is far from dormant. About 98 percent of it is covered by ice, and that ice is constantly moving. Temperatures can range from above zero in the South Shetlands and Antarctic Peninsula to the unbearable frozen lands near the South Pole. As an active volcano, Deception Island is a pot of extreme conditions. There are spots where the sea boils at 212 degrees Fahrenheit, while in others it can be freezing at below 32. And while the sun rarely shines on the long, dark Antarctic winters, nighttime never seems to fall on summer days.

While tourists come to Antarctica for its beauty and remoteness, scientists are all business. What they find could affect the lives of people thousands of miles away; if experts are right, and the West Antarctic ice sheet has started melting irreversibly, what happens here will determine if cities such as Miami, New York, New Orleans, Guangzhou, Mumbai, London and Osaka will have to regularly battle flooding from rising seas.

Antarctica "is big and it's changing and it affects the rest of the planet and we can't afford to ignore what's going on down there," said David Vaughan, science director of the British Antarctic Survey.

Often, scientists find something other than what they were looking for. Last year researchers calculated that ice on the western side of the continent was melting faster than expected.

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Last month, scientists researching vital geology in that melting were looking a half mile under the ice in pitch dark and found a surprise: fish a half foot long and shrimp-like creatures swimming by their cameras.

Geologists are entranced by Antarctica's secrets. On a recent scientific expedition led by Chile's Antarctic Institute, Richard Spikings, a research geologist at the University of Geneva, wielded a large hammer to collect rock samples in the South Shetlands and the Antarctic Peninsula. Curious members of a penguin colony on Cape Legoupil watched as he pounded on slabs of black granite and diorite rising out of the southern ocean. By the end of the two-week trip, his colleagues had jokingly begun calling him "Thor."

"To understand many aspects in the diversity of animals and plants it's important to understand when continents disassembled," Spikings said. "So we're also learning about the real antiquity of the Earth and how (continents) were configured together a billion years ago, half a billion years ago, 300 million years ago," he said, adding that the insights will help him understand Antarctica's key role in the jigsaw of ancient super continents. With names like Rodinia, Gondwana and Pangaea, scientists believe they were significant landmasses in Earth's history and were periodically joined together through the movement of plates.

Because there is no local industry, any pollution captured in the pristine ice and snow is from chemicals that traveled from afar, such as low levels of lead found in ice until it was phased out of gasoline, or radiation levels found from above-ground nuclear tests thousands of miles away and decades ago by the U.S. and the Soviet Union, Vaughan said.

The ice tells how levels of carbon dioxide, the heat-trapping gas, have fluctuated over hundreds of thousands of years. This is also the place where a hole in the ozone layer, from man-made refrigerants and aerosols, periodically parks for a couple months and causes trouble. It happens when sunlight creeps back to Antarctica in August, triggering a chemical reaction that destroys ozone molecules, causing a hole that peaks in September and then closes with warmer weather in November.

Exploring Antarctica is something Chilean Alejo Contreras, 53, began dreaming about as a teen after reading Robert Falcon Scott's journal of his journey to the South Pole. When Contreras finally got to the South Pole in 1988, he stopped shaving his beard, which today hangs down to his chest and often goes every which way, similar to his explorations.

Antarctica is "like the planet's freezer," said Contreras, who has led 14 expeditions to the continent. "And none of us would dare litter the ice."

Because of the pristine nature of the bottom of the world, when a meteorite lands here it stays untouched. So researchers find more meteorites, often from nearby Mars, including one discovered nearly 20 years ago which had scientists initially thinking, incorrectly, they had found proof that life once existed on Mars.

This is a place with landscapes out of an alien movie set. NASA uses the remoteness of the continent to study what people would have to go through if they visited Mars. The dry air also makes it perfect for astronomers to peer deep into space and into the past.

During a recent trip to Deception Island, Peter Convey, an ecologist for the British Antarctic Survey who has been visiting Antarctica for 25 years, braved heavy rain, near freezing temperature and winds of more than 20 knots to collect samples of the spongy green and brown mosses that grow in patches on the ash of the volcanic island's black rock mountains. He was looking for clues in their genetics to determine how long the species have been evolving on Antarctica, in isolation from other continents.

"I've been lucky and I've gone to the middle of the continent, so I've been isolated from the next human being for 400 to 500 kilometers (250-300 miles)," Convey said. In this remoteness are odd life forms, raising hope that life might once have existed in other extreme environments such as Mars or is even now hidden below the ice of Jupiter's moon Europa.

"This is one of the more extreme places where you could expect to find life. It's even here," said Ross Powell, a Northern Illinois University scientist who in January was using a remote-controlled submarine deep under the ice in another part of Antarctica to figure out about melting, when the unusual fish and shrimp-like creatures swam by.

About 4,000 scientists come to Antarctica for research during the summer and 1,000 stay in the more forbidding winter. There are also about 1,000 non-scientists - chefs, divers, mechanics, janitors and the priest of the world's southernmost Eastern Orthodox Church on top of a rocky hill at the Russian Bellinghausen station.

But the church on the hill is an exception, a glimmer of the world to the north. For scientists, what makes this place is the world below, which provides a window into mankind's past and future.

"Antarctica in many ways is like another planet," said Jose Retamales, the director of the Chilean Antarctic Institute, while aboard a navy ship cruising along Deception and the other South Shetland islands. "It's a completely different world."