Scientists came to Greenland on an unprecedented mission to drill for rocks that would reveal the fate of the country’s fast-melting ice sheet. A sudden crack in the ice threatened their experiment. Read more:The Greenland Ice Sheet contributes more to sea level rise than any other ice mass. If it disappeared, it would raise global sea levels by 24 feet, devastating coastlines home to about half the world’s population. Computer simulations and modern observations alone can’t precisely predict how Greenland might melt. Greenland’s bedrock holds clues. It was present the last time the ice sheet melted completely and contains chemical signatures of how that melt unfolded. It could help scientists predict how drastically Greenland might change in the face of today’s rising temperatures. But scientists have less material from under the ice sheet than they do from the surface of the moon. So this spring, a team from Columbia University’s Lamont-Doherty Earth Observatory made an unprecedented effort to drill through more than 1,600 feet of ice and uncover the bedrock below.Climate reporter Sarah Kaplan was there too. She arrived just after a thin crack appeared in the ice around the drill, threatening the project and its ability to unearth the future.