Ask a Geologist:Impact Craters

By: Evan Bjonnes

About Me

Evan Bjonnes● Pet-parent to a dog (Mr. Pibb) and

a cat (Tater Tot)● I use computers to understand

how impact craters form on different planets and moons

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About Me

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Evan Bjonnes● Pet-parent to a dog (Mr. Pibb) and

a cat (Tater Tot)● I use computers to understand

how impact craters form on different planets and moons

● My favorite mineral is Celestine

Meteorites

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● Meteorites are how space materials come to Earth

Meteorites

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● Meteorites look like shooting stars because of our atmosphere

Meteorites

● Traveling through the atmosphere burns the outside of a meteorite

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Meteorites

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From the Smithsonian National Museum of Natural History

● We study meteorites to learn about where they came from

Meteorites

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● Some meteorites have beautiful patterns inside

Widmanstätten Pattern

Meteorites

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● Some meteorites have beautiful patterns inside

Pallasite

Impacts!

● Objects hitting at a high speeds –Impact Cratering!

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This impact is not fast enough to form an

impact crater

Types of Craters

● Micro Impacts● Very small craters!

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Destroyed Solar Panel

Types of Craters

● Simple Craters

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Meteor Crater,Arizona

Types of Craters

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Types of Craters

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Types of Craters

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Types of Craters

● Meteor Crater● Simple Crater in

Arizona● School-bus sized

meteorite!

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Types of Craters

● Complex Craters● Uplifted peak in the

center

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Tycho Crater,The Moon

Types of Craters

● Complex Craters

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Types of Craters

● Peak Ring Craters

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Schrödinger Crater,The Moon

Types of Craters

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Types of Craters

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Types of Craters

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Types of Craters

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Types of Craters

● Multiring Basins

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Orientale Basin,The Moon

Ongoing Questions

● How do the largest impact basins form?

● How does the type of material affect an impact?

● How does a crater evolve after it forms?

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Orientale Basin,The Moon

Why Do We Care?

● We only have 1 Solar System!● Studying impacts helps us

understand how our planet and Solar System grew

● Impacts affect manyparts of geologicevolution

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Recent Events

● Airbursts● Tunguska

Event - 1908

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Recent Events

● Airbursts● Tunguska

Event - 1908

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Recent Events

● Airbursts● Chelyabinsk

Event –2013!

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Question Time!

My Interests

● I use computer models to understand how very large impact craters form

● Make models of the Moon, Jupiter’s moons, and Venus

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Valhalla BasinCallisto

Jupiter’s Moon