What Happened to the Ancient Martian Atmosphere?

Dave BrainUniversity of Colorado Boulder

29 July, 2015Western Alliance Conference

The Martian Atmosphere Today

Cold ThinToxic

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Two Mysteries in One

https://www.youtube.com/watch?v=zm3b3kwzSF4&feature=youtu.be

Up

Down

Where Did the Atmosphere Go?

What Causes the ‘Ups’?Photons Solar Wind

Magnetic Field

Solar Energetic Particles

Drivers, Reservoirs, and Escape

MarsAtmosphere andVolatileEvolutioN

Neutrals and Ions Plus Evolution

IUVS NGIMSIon-Related Properties and Processes

LPWMAGSTATIC

Sun, Solar Wind, Solar Storms

SWIAEUV

SWEASEP

The MAVEN Science Instruments:

IUVS Observations of Atomic Components of H2O and CO2 on Their Way to Escaping

Expected Escape Pattern

Escaping Oxygen Ions

Close Encounter With Comet Siding Spring

Breckland Skies Observatory

A comet passed close to Mars on October 19, 2014

A Martian Meteor Shower

Blue = before CSSRed = after