At an extremely remote Antarctic outpost,关键字3 scientists have unearthed a pristine sample of our planet's history.

It's an ice core 2,800 meters, or some 1.7 miles, long. But it's not just the length that's so significant. The ice contains preserved pockets of Earth's air from some 1.2 million years ago, if not more. Previous ice cores provided direct evidence of our planet's climate and environment from up to 800,000 years ago.

So, this is a giant leap. The team drilled so deep they reached the continent's bedrock.

---

You May Also Like

---

---

"We have marked a historic moment for climate and environmental science," Carlo Barbante, a polar scientist and coordinator of the ice core campaign called "Beyond EPICA - Oldest Ice," said in a statement.

SEE ALSO: If a scary asteroid will actually strike Earth, here's how you'll know

An international group of researchers excavated the ice at Little Dome C Field Camp in Antarctica, located 10,607 feet (3,233 meters) above sea level. They beamed radar down into the subsurface and used computer modeling of the ice flow to determine where this ancient ice was likely to be. And they were right.

Mashable Light Speed Want more out-of-this world tech, space and science stories? Sign up for Mashable's weekly Light Speed newsletter. By clicking Sign Me Up, you confirm you are 16+ and agree to our Terms of Use and Privacy Policy. Thanks for signing up!

This was no easy feat. Atop the Antarctic plateau, summers average minus-35 degrees Celsius, or minus-31 degrees Fahrenheit.

The location of Little Dome C research base in Antarctica. Credit: Beyond EPICA / EU Ice core drilled from the recent Beyond EPICA - Oldest Ice expedition. Credit: Scoto © PNRA / IPEV

Although paleoclimatologists, who research Earth's past climate, have reliable methods of indirectly gauging our planet's deep past — with proxies such as fossilized shells and compounds produced by algae — direct evidence, via direct air, is scientifically invaluable. For example, past ice cores have revealed that the heat-trapping carbon dioxide levels in Earth's atmosphere today have skyrocketed — they're the highest they've been in some 800,000 years. It's incontrovertible evidence of Earth's past.

Scientists expect this even older ice core, however, will reveal secrets about a period called the Mid-Pleistocene Transition, lasting some 900,000 to 1.2 million years ago. Mysteriously, the intervals between glacial cycles — wherein ice sheets expanded over much of the continents and then retreated — slowed down markedly, from 41,000 years to 100,000 years.

"The reasons behind this shift remain one of climate science's enduring mysteries, which this project aims to unravel," the drilling campaign, which was coordinated by the Institute of Polar Sciences of the National Research Council of Italy, said in a statement.

This Tweet is currently unavailable. It might be loading or has been removed.

Now, the drilling is over. But the campaign to safely transport the ice back to laboratories, and then scrutinize this over-million-year-old atmosphere, has begun.

"The precious ice cores extracted during this campaign will be transported back to Europe on board the icebreaker Laura Bassi, maintaining the minus-50 degrees Celsius cold chain, a significant challenge for the logistics of the project," explained Gianluca Bianchi Fasani, the head of ENEA (National Agency for New Technologies, Energy, and Sustainable Economic Development) logistics for the Beyond EPICA expedition.

These historic ice cores will travel in "specialized cold containers" as they ship across the globe, far from the depths of their Antarctic home.