The Larsen C ice shelf as seen by the Synthetic Aperture Radar (SAR) instrument on the Sentinel-1A satellite on June 28th. Image: NASA Earth Observatory

Like that painful hangnail you’ve been eyeing for days—except billions of times larger, made of ice not keratin, and studied by dozens of scientists worldwide—a Delaware-sized glacier along Antarctica’s Larsen C ice shelf is hanging by a thread, poised to break off into the ocean any day now.

It’s one of the largest iceberg calving events scientists have ever witnessed.