There May Be a Massive Impact Crater Hidden Under Antarctic Ice

The impact record humanity has assembled is built almost entirely on what has been found on land - and land represents less than a quarter of the planet's surface. Randall makes the arithmetic explicit. For every impact that strikes land, three strike the ocean. That means the craters, the geological signatures, and the event record we have been working from represents a fraction of the actual impact history of this planet - and the fraction we are missing is the larger one by a significant margin.

The distribution of known craters is itself revealing. Europe, Scandinavia, Canada, the United States, and increasingly Russia account for the majority of identified impact sites - regions of dense human habitation and extensive geological survey. What lies under Antarctica remains largely unknown, though Randall notes there is already evidence pointing toward a significant crater beneath the ice. The ocean floor is almost entirely unexamined from an impact perspective. Compounding that gap is the abundance of low density impactors - objects approximately ten times more common than iron meteorites, which leave far less obvious signatures even when they do strike land. Randall’s conclusion is one that reframes the entire conversation about cosmic impact frequency - we have not been counting most of what has hit this planet, and the true number of events capable of affecting human civilization is almost certainly far higher than the crater record alone suggests.