Most of Earth’s impact craters await discovery
Ninety or more cavities wider than 1 kilometer remain to be found
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
Earth’s surface could hide some big blemishes. More than 90 impact craters larger than a kilometer across await discovery, researchers estimate in the Sept. 1 Earth and Planetary Science Letters.
While scars from meteor impacts pepper other planets — Mars alone has more than 300,000 — erosion has buffed away most of Earth’s craters. Only 188 confirmed impact craters of any size dot Earth’s surface, but more are out there. Pairing estimates of how often space debris whacks Earth and how fast erosion collapses the resulting holes, researchers calculate that about 350 craters wider than 250 meters remain undiscovered.
Crater hunters should note that accumulated sediment probably obscures many of these craters.
Lost and found
Earth has 188 known impact craters (including ones below 0.25 kilometers in diameter). Researchers have estimated that 350 more big ones are out there awaiting discovery. Confirmed craters straddling two size ranges are counted as half for each.
Source: S. Hergarten and T. Kenkmann/Earth and Planetary Science Letters 2015
