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Venus. Mars. Earth’s Moon (S. Pole). Mercury. Mistastan Lake, New Foundland, Canada 28 Km 38,000 years. Barringer Meteor Crater, AZ 1.18 km 49,000 years. Wolf Creek, Australia 0.875 Km 300,000 years. Bosumtwi, Nigeria 10.5 Km 1.3 Million years.
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Venus Mars Earth’s Moon (S. Pole) Mercury
Roter, South Africa 2.5 km 5 Million years
Chicxulub, Mex 170 Km 65 Ma
Deep Bay, Sask. 13 km 100 Million years Clearwater Lakes, Sask. 32 km/22km 290 Million years
Radar Image of NEO 1999JM8 Missed Earth by 5 million km in 1990, 6 million km in 1999 Average diameter 3.5 km
Tunguska Event, 1908, Russia 80 million trees knocked down over 2,150 square kilometres (830 square miles
Tunguska Event 1908 Equivalent to a 100 MT Nuclear Bomb Blast
Question If cratering rate on Earth is same as our Moon, why are their so few craters preserved?
Apollo 14 site spherules (~ 0.2 mm diameter) Argon40/Argon39 dates (accuracy ~ +/- 200 MY)
Apollo 14 site spherules (~ 200 micro-meters diameter) Argon40/Argon39 dates (accuracy ~ +/- 200 MY) => 26 Ma periodicity
1 BY averaging bins Black and opaque spherules only
Question: If cratering rate on Earth is same as our Moon, why are their so few craters preserved? Answer: Erosion