Impact Craters Leave an Impression…

Andy Saulietis Craters are everywhere! The Moon LPL / UA NASA Apollo 17

Mercury NASA/GSFC Asteroids NASA

Mars NASA

Even Earth… Meteor Crater, AZ Geoffrey NotkinUSGS

So what causes craters? Asteroids and Comets! NASA Left over building blocks of the solar system (~5 billion years old) Vary in size, from a few feet to a few miles Millions of potential meteors in our solar system alone Travel in excess of 20,000 mph

When these objects collide with another body, like the Earth, the result is a crater. Meteor Crater, AZ Wright, S.P Size: 150 Feet Across 1 Composition: Nickel- Iron 1 Speed: 28,600 MPH 1 Age: 50,000 years old 1 Energy: 2.5 Megatons 1 1 Barringer Meteor Crater Site

NASA/GSFC Shoemaker-Levy 9

Why do some planets have more craters than others? NASA/GSFC Atmosphere Oceans Plate Tectonics Location

So why do we care? NASA/GSFC Extinction

Estimated that there have been at least 5 mass-extinctions in Earth’s history 1 Up to 90% of all species killed off 2 At least one is believed to have been caused by a meteorite 1 65 Million Years ago, Yucatan Penninsula 2 >100 Miles across 2 Force Greater than 1,000,000 megatons 3 1 Lee Siegel, space.com 2 NASA/GSFC 3 Arnett, Bill, UA