What Is Astrobiology And Why Do We Care?

Bruce JakoskyLaboratory for Atmospheric and Space Physics

University of Colorado at Boulder

9 February 2010

Earth

ENVIRONMENTAL CONDITIONS NECESSARYFOR LIFE

Liquid water

Access to biogenic elements

Source of energy to drive chemical disequilibrium

Mars

Venus

Europa

Enceladus

Places that meet/met requirements for life

• Meet/met all requirements:– Earth

– Mars

– Europa

• Meet some/most requirements and may meet all of them:– Enceladus

– Ganymede

– Callisto

– Titan

• May have met them in the past:– Venus

– Io

Particularly Relevant Spacecraft Missions

• Ongoing– Mars Reconnaissance Orbiter– Spirit and Opportunity– Phoenix– Cassini– New Horizons– MESSENGER

• Upcoming– Mars Science Laboratory– MAVEN– JUNO

• Possible future missions– Outer Planet Flagship– Mars Sample Return– Comet sample return– Asteroid sample return– Lunar South Pole / Aitken Basin

sample return

The MAVEN Spacecraft

Potential Importance of the Role of Loss to Space

• The history of liquid water and of the atmosphere determine Mars’ potential for life throughout time.

• There is abundant evidence for climate change and atmospheric evolution.

• Loss of atmospheric CO2, N2, and H2O to space has been an important mechanism for atmospheric evolution, and may have been the dominant mechanism.

Only by understanding the role of escape to space will we be able to fully understand the history of the atmosphere, climate, and water, and thereby understand Martian habitability.

MAVEN Will Measure the Drivers, Reservoirs, and Escape Rates

• MAVEN will determine the present state of the upper atmosphere and today’s rates of loss to space.

• Essential measurements allow determination of the net integrated loss to space through time.

Solar Input

Neutral Processes

Plasma Processes

Launch: November 18, 2013

Ten Month Ballistic Cruise to Mars

Orbit Insertion:16 Sept 2014

One Year of Science Operations

MAVEN Mission Architecture

CU/LASP, GSFC, UCB/SSL, LM, JPL

Launch Year

MROMRO

Mars ExpressCoop

Mars ExpressCoop

OdysseyOdyssey

MERMER

2013 2016 2018 & Beyond20112009Operational

MAVEN MAVEN

PhoenixPhoenix

Mars Science LabMars Science Lab

Trace Gas Orbiter

Trace Gas Orbiter

NASA’s Mars Exploration Program

Why do we care?

Student perspectives on finding life elsewhere (1 of 2):

• Finding bacteria elsewhere would be scientifically interesting, but only finding extraterrestrial intelligence would be truly profound.

• It won’t make much difference to most people; their lives would go on pretty much as before.

• We should solve our own problems here on Earth before we even go looking for life elsewhere.

• Extraterrestrial intelligence will help us to save the world by solving all of our current problems.

• Extraterrestrial life will destroy our civilization, either by intent or by accident.

Student perspectives on finding life elsewhere (2 of 2):

• The existence of extraterrestrial life or intelligence would be inconsistent with the view of modern religions.

• Modern religions have dealt with scientific discoveries and societal changes in the past, and they probably can adapt to deal with a discovery of life elsewhere (if there’s even a conflict).

• We’ve already discovered extraterrestrial life and the government is hiding it, probably in a hangar in New Mexico.

• We may not have discovered it yet, but the government is covering up anyway.

Searching for life elsewhere:

Mars sample return

Europa surface and ocean

Earth-like planets

Extraterrestrial intelligence?

“There are two possibilities. Maybe we’re alone. Maybe we’re not. Both are equally frightening.” Arthur C. Clarke

“We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.” T. S. Eliot