Deep beneath Antarctica, researchers drill ice cores filled with tiny bubbles of ancient air, sealed into the ice for hundreds of thousands of years — letting them sample the atmosphere of a world no living human ever breathed.

When snow falls on the interior of Antarctica, it does not melt. It piles up, year on year, and the weight of each new layer presses the layers below into ice. As that happens, something useful is trapped. Air fills the spaces between snowflakes, and as the snow compacts into solid ice, that air is [...] The post Deep beneath Antarctica, researchers drill ice cores filled with tiny bubbles of ancient air, sealed into the ice for hundreds of thousands of years — letting them sample the atmosphere