Official count puts Earth’s number of large impact craters at just 128

Science : Wind and water movement, tectonic activity, and other processes have continually eroded Earth’s surface to a degree unseen on Mars or the Moon. As a result, there are far fewer impact craters visible on Earth’s surface compared with the 300 000 on Mars and the uncountable millions on the Moon. In 2014, it was determined that all the craters on Earth with a diameter larger than 85 km had been discovered. Now, Stefan Hergarten and Thomas Kenkmann of the University of Freiburg, Germany, have extended that down to all craters larger than 6 km across. The determination that no more large craters will be found is based on impact and erosion rates, theoretical crater distribution, and the number of craters actually found. Hergarten and Kenkmann go on to suggest that only about 350 craters between 0.25 km and 6 km in size remain to be discovered.