NRC Planetary Science Decadal Survey

Wendy CalvinProf. Geological Sci & Eng,

University of Nevada - Reno

Vice-Chair Mars Sub-Panel

for Western Space Grant Directors MeetingDRI, 18.Sept.09

Decadal Surveys

Chartered by NASA, but provided by NRC as advisory arm of the NAS.

Independent assessment of scientific priorities in a given area.

Earth Science just completed (2007). Astronomy/Astrophysics and Planetary currently

underway. Identify and Prioritize flight investigations believed

to be > 450$M life cycle cost. Include infrastructure, R&A, education, technology

New Frontiers in the Solar System (2003)

Fundamental Science Questions 1st Billion Years of Solar System History Volatiles and Organics stuff of life Origin and Evolution of Habitable Worlds How Planetary Systems Work

Example Recommended Missions Europa Geophysical Explorer Venus In-Situ Jupiter Polar Orbiter S. Pole Aiken (Lunar) Sample Return Mars Network Mars Sample Return

Planetary Science 2013-2022

Overview of planetary science. Survey the state of knowledge, recent discoveries. Inventory top-level science questions that guide

flight missions. Small (Discovery), Medium (New Frontiers), Large

(Flagship) mission classes. (New) priorities for Mars and Earth’s Moon to be

integrated with the rest of the Solar System. (New) assessment and cost modeling of flight

concepts. (New) Astrobiology included in sub panels rather

than separate sub-panel.

Committee Structure

Steering Committee (Squyres, Soderblom) Vice-Chair of each sub panel (5) 9 others not affiliated with any subpanel

Sub-Panels Primitive Bodies (Asteroids, Comets, KBOs,

Meteorites, IDPs) Inner Planets (Mercury, Venus, Moon) Mars Giant Planets (JSUN, exoplanets, rings, fields) Satellites (Europa, Ganymede, Titan Enceladus,

and many, many others)

http://sites.nationalacademies.org/SSB/CurrentProjects/ssb_052412

Mars Panel

13 Members Represent science from core to atmosphere

Strategic missions and design well-considered through MEPAG community process. Goals and Objectives “Living” Document

Life, Climate, Geology/Geophysics, Human Exploration Plans for 2016, 2018 Missions relatively stable

2016 Trace Gas Orbiter, 2018 – Rover (Astrobio) International collaboration developing

Exo-Mars, Mars Sample Return Just had 1st meeting, briefings from MEPAG

community and mission studies. Community white papers just delivered.

Process/Timeline

Sub panels meet, gather information, propose missions for study. Include “White papers” from community Each sub-panel has 2 meetings between Aug-Nov 2009

Steering committee prioritizes input from sub-panels into cross-solar system themes and goals. Strive for consensus and community ownership Fit within current budget constraints

Draft document from sub panels Spring 2010 Draft full report Fall/Winter 2010 External review and release of final report summer

2011.

2003 Mars Themes / Key Questions

Mars as a potential abode of life Does/Did life exist, how habitable?

Water, atmosphere, and climate Sources, sinks, volatile reservoirs Atm evolution, dynamics, atm escape 3D distribution of water in the crust

Structure and evolution of Mars Rock types, origin of crustal magnetism Internal structure, core dynamo Chronology, oxidation with depth

Why Mars?

1. Mars offers crucial information about the early evolution, internal structure, and origin of the terrestrial planets, including Earth.

2. Timeframe for evolution of life on Earth is largely absent from the rock record, but this era is preserved on Mars.

3. Mars provides a means to approach, and possibly answer, origin and evolution of life questions.

4. Excellent opportunity to investigate short- and long-term climate change.

5. Mars science has benefitted from a focused, dedicated program of exploration.

10

Competitive PI-Led Missions

MER Focused Technology

MRO Focused Technology

MSL Focused Technology

MEP—An Integrated Set of ActivitiesCreating a True Program Structure

Advanced Planning & Community InputResearch and E/PO Programs

Base Technology

2007Mars

Reconnaissance Orbiter

Mars Reconnaissance

Orbiter

2001 2003 2005

Curiosity

1996

Phoenix

2011Mars Global

SurveyorMars Global

Surveyor

OpportunitySpirit

Mars OdysseyMars Odyssey

Mars Pathfinder

Year of Launch2013

MAVENMAVEN

Strategic, Core Missions

Last Decade Discoveries: Diverse Planet with Complex History

Mars has areas with diverse mineralogy, including alteration by water, with a change in mineralogy over time and spatial diversity of environments.

In situ confirmation of increased water activity in the past.Pervasive water ice in globally distributed, near-surface reservoirs.

Sources, phase changes, and transport of volatiles (H2O, CO2) are known & some are quantified.

Increasing evidence for geologically recent climate change.Dynamic change occurring even today: landslides, new gullies, new

impact craters, changing ice cover.Presence of methane indicative of active chemical processes either

biogenic or abiotic. Based on much of the above, the perception of Potential for past Life

has increased, and Modern Life may still be possible.

Last Decade Discoveries: Diversity of Environments

-12

Lyell

Steno

Smith

Gilbert area

PHX

Victoria Crater

MER

Hesperian subsurface water, diagenesis

Chemistry and morphology indicate changing environments throughout geologic history

• Acidic waters at Meridiani• Basic waters at Phoenix landing site• Mineralogy: clays to sulfates to oxides

MRO

Melas Chasma

Large-scale sedimentary structures

MRO

MRO

Delta, showing phyllosilicate layers

Eberswalde Delta

Past Decadal Results: Wide variety of sedimentary deposits

-13

MeridianiMER

Fine-scale sedimentary structures

Depositional processes created a sedimentary record

• Developed in topographically low areas

• Spectacular stratification at multiple scales

• Evidence of persistent standing water, lakes

• Sediments systematically change in character with time

• Multiple facies recognized

-14

Gamma Ray Spectrometer• Global hydrogen

abundance and equivalent H2O

• Ground ice to +/-60° in high abundance

ODY

Global Near-Surface Reservoirs of Water

Past Decadal Results: Distribution of Modern Water

SHARAD and MARSIS• Nearly pure water ice • Distinct layering• No deflection of crust• Ice-cored lobate debris

aprons in mid-latitudes

MRO MEX

Phoenix results PHX

Past Decadal Results: Periodic Climate Change

Volatile-rich, latitude dependent deposits (mantle, glaciers, gullies, viscous flow) coupled to orbitally-forced climate change

Periodicity of layering in the north polar cap deposits as well as sedimentary deposits

• Latitude dependent mantle

Modeled Ice Table Depth [m]

MGS, ODY, MEX MRO

Evidence of an active subsurface?

Biotic?

Abiotic?

courtesy Mark Allen

courtesy Lisa Pratt

NAIDetection of Methane on Mars

Cou

rtes

y M

ike

Mum

ma

NAI, R&A

Past Decadal Results:

Modern Methane

MEX NAI R&A

Sulfates Anhydrous Ferric OxidesClays

Past Decadal Results:

Mars Planetary Evolution

Hydrous Mineralogy Changed Over Time

• Phyllosilicate minerals (smectite clay, chlorite, kaolinite…) formed early

• Evaporates dominated by sulfate formed later with opal/hydrated silica

• Few hydrated mineral deposits since

Evolution of Aqueous, Fluvial and Glacial, Morphology with Time

• Valley networks, lake systems

• Gullies • Viscous flow, glaciers,

latitude dependant mantle

acidicNeutral pH

Questions for the Next DecadeIntegrating the MEPAG science priorities and the programmatic factors,

these specific questions are highest priority for the next decade.

• What is the diversity and nature of aqueous geologic environments? (Goal I, II, III--MSL will contribute)

• What is the detailed mineralogy of the diverse suite of geologic units and what are their absolute ages? (Goal II, III)

• Are reduced carbon compounds preserved and, if so, in what geologic environments? (Goal I--MSL may contribute)

• What is the complement of trace gases in the atmosphere and what are the processes that govern their origin, evolution, and fate? (Goal I, II, III)

• How does the planet interact with the space environment, and how has that affected its evolution? (Goal II—addressed by MAVEN mission)

• What is the record of climate change over the past 10, 100, and 1000 Myrs? (Goal II, III)

• What is the internal structure and activity? (Goal III)