In 1966, the U.S. Army drilled through 1.4 km of Greenland ice; decades later, forgotten soil from the core revealed preserved leaves and twigs

Sometimes the most important scientific discoveries aren’t made in a lab. They are made in a long-forgotten box that sat in a freezer for more than 50 years.

And that’s what happened with a tube of frozen dirt pulled out of Greenland by the US Army in 1966. According to a study published in the Proceedings of the National Academy of Sciences (PNAS), inside that soil sample was something nobody saw coming: preserved leaves, twigs and moss from a Greenland that had no ice at all.