Most of Earth’s impact craters await discovery
Ninety or more cavities wider than 1 kilometer remain to be found
![Pingualuit Crater in northern Canada](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/06/ts_craters_free.jpg?fit=860%2C460&ssl=1)
HIDDEN HOLES Hundreds of undiscovered craters wider than a quarter-kilometer across probably dot Earth’s surface, new research estimates. The Pingualuit Crater in northern Canada (shown) measures 3.44 kilometers wide.
Courtesy of Denis Sarrazin/NASA Earth Observatory