Workshop on
Spectroscopy of the Martian Surface: What Next?

 

Held at

Lunar and Planetary Institute, Houston, TX
June 10-11, 1999

 

Edited by

L. Kirkland, J. Salisbury, J. Mustard,
R. Clark, P. Lucey, and S. Murchie


Sponsored by

Lunar and Planetary Institute
JPL Mars Program Office


Convener
Laurel Kirkland

 

 

CLICK HERE FOR THE REPORT AS A PDF DOCUMENT


Laurel Kirkland's home page


CONTENTS

Introduction

Historical note

Letters

Recommendations for the next spectral data set of Mars

Recommendations for supporting research

Recommendations for the proposed Mars airplane

List of participants

Program

Abstracts (In Adobe Acrobat PDF Format)

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Bell, J., Fifty Years Of Mars Surface and Atmospheric Composition from Telescopes: Highlights and Implications For Spacecraft Studies

Clark, R., Mapping the Surface Mineralogy of Hydrothermal Alteration Systems: Applications to the Geologic History of Mars and the Search for Past Life

Farrand, W., Sub-pixel Detection and Mapping of Spectrally Unique Materials on Mars using ISM Data

Farmer, J., Environmental and Mineralogical Controls on Fossilization: Key Elements in a Strategy for Mars Exopaleontology

Erard, S., What ISM told us about Mars

Erard, S. and J-P. Bibring, OMEGA, the Imaging Spectrometer On Board Mars Express

Hanel, R., 1971 Mariner Mars Infrared Interferometer Spectrometer (IRIS)

Hansen, G., Remote Sensing Spectroscopy of the Polar Regions of Mars

Herr, K. and L. Kirkland, 1969 Mariner Mars Infrared Spectrometer (IRS): Lessons for Future Exploration

Keim, E., The SEBASS Hyperspectral Imaging Spectrograph: Instrument Description and Sample Thermal Images Obtained Near Flagstaff, Arizona and Mesquite, Nevada

Mustard, J., Review of the 1989 ISM Instrument and Results

Pieters, C., J. F. Mustard, and S. L. Murchie, Aladdin Instruments at Mars

Young, S., Use of Thermal Hyperspectral Imagery in Terrestrial Surface Characterization


Introduction

Members of the Mars infrared spectral community desired to assess what spectral instrument will best serve the Mars program and spectral community after the successful flight of currently planned instruments. It was felt this issue needed to be addressed, given the shift of the NASA Mars program toward a search for regions conducive to the preservation of biomarkers, and the desire for sample return. To this end, leaders of the planetary community with expertise in spectroscopy and remote mineral identification met to discuss the state of understanding of Mars surface composition, and to assess what critical gaps may exist: 1) after the successful completion of planned measurements of Mars; and 2) in research programs to support investigations of the current and planned data sets. Participants also discussed the proposed Mars airplane. This report summarizes our consensus.

To support the selection of landing sites that may preserve biomarkers, participants agreed that the most critical gap that will remain is a spectral data set containing very high information content spectra of targeted regions. Mineralogy is an essential tool to assess ancient and modern environments on Mars that may have been conducive to the support and preservation of life and biomarkers. Reflectance and emission spectroscopy remain the most capable method for remote mineral identification. Experience gained from spectral data sets of Mars and Earth has shown that an unambiguous interpretation requires spectra with both high spatial resolution and very high information content. High information content is obtained by measuring with broad spectral range, high spectral resolution, and high signal to noise ratio.

Participants concluded that there are two critical gaps in the ability of the community to interpret current and planned spectral data sets. First is a lack of a widely accepted method to quantitatively examine remotely sensed spectra. Second is the lack of adequate spectral libraries available to the entire community that contain the needed range of minerals, coatings, and particle sizes.

Selecting among potential landing and sample return sites will be aided by a clear, unambiguous interpretation of spectra measured from orbit. To provide adequate support for the landing site selection process, we recommend the measurement from orbit of high information content spectra of targeted regions, and the development of the two listed research areas. This will provide essential tools in the phased approach to Mars exploration that NASA has developed. Additional details on workshop recommendations are contained in the Letters within this report. We strongly encourage NASA and the Mars community to consider these recommendations in planning for future research programs.

 

Sincerely,

Participants of the workshop, "Spectroscopy of the Martian Surface: What Next?"

Jim Bell		Diana Blaney		Phil Christensen	Ben Clark
Roger Clark 		Stephane Erard		Jack Farmer		William Farrand
Rudy Hanel		Gary Hansen		Ken Herr		Eric Keim
Laurel Kirkland		Melissa Lane		Paul Lucey		Richard Morris
Scott Murchie		John Mustard		Carle Pieters		Jack Salisbury
Steve Saunders		Allan Treiman 		Steve Young

 

Participant

Affiliation, and instruments built/building

Jim Bell

Cornell University

Diana Blaney

Jet Propulsion Laboratory

Phil Christensen

Arizona State University; 1997 TES PI; 2001 THEMIS PI; '01, '03, '05 Mini-TES PI

Ben Clark

Lockheed-Martin

Roger Clark

USGS; 1997 TES Co-I

Stéphane Erard

CNES

Jack Farmer

Arizona State University

William Farrand

Space Science Institute

Rudy Hanel

GSFC (retired); 1971 IRIS PI

Gary Hansen

U. Hawaii

Ken Herr

Aerospace Corporation; 1969 IRS Co-I

Eric Keim

Aerospace Corporation

Laurel Kirkland

Lunar and Planetary Institute; Convener

Melissa Lane

NASA-JSC

Paul Lucey

U. Hawaii

Richard Morris

NASA-JSC

Scott Murchie

Johns Hopkins U.-Applied Physics Laboratory

John Mustard

Brown University

Carlé Pieters

Brown University

Jack Salisbury

Johns Hopkins University

Steve Saunders

Jet Propulsion Laboratory

Allan Treiman

Lunar and Planetary Institute

Steve Young

Aerospace Corporation

IRS = 1969 Mariner Mars 6/7 Infrared Spectrometer
IRIS = 1971 Mariner Mars 9 Infrared Interferometer Spectrometer
TES = 1997 Global Surveyor Thermal Emission Spectrometer
Co-I = Co-Investigator
PI = Principal Investigator


Historical Note

This workshop had an unusual breadth of researchers present, and included expertise in spectroscopy of Mars, Earth, and the moon; from the both NASA and the DOD/Intelligence community; and in laboratory spectral research and computational spectral analysis.

However, an interesting historical note was the presence of all three builders of the only thermal infrared spectrometers ever sent to Mars. It is the first, and will perhaps be the only time, that all three have been together:

Builders of thermal infrared spectrometers flown to Mars, shown left to right below:
Kenneth C. Herr (1969 Mariner Mars 6/7 Infrared Spectrometer, IRS)
Rudolf A. Hanel (1971 Mariner Mars 9 Infrared Interferometer Spectrometer, IRIS)
Philip R. Christensen (1997 Global Surveyor Thermal Emission Spectrometer, TES)

 

Click here for larger image

Photo Credit: Debra Rueb, LPI Staff Photographer
Taken during the workshop, at the entry to the LPI

 

 


Recommendations: Next Spectral Data Set

On June 10 - 11, 1999 the workshop "Spectroscopy of the Martian Surface: What Next?" was held at the Lunar and Planetary Institute in Houston, TX. At this workshop, leaders of the science community with expertise in spectroscopy and remote mineral identification met to discuss the state of understanding of Mars surface composition, and to assess what critical gaps may exist after the successful completion of currently planned Mars missions. Participants agreed that the most critical gap that will remain is a spectral data set containing targeted, very high information content measurements to support the selection of landing sites that may preserve biomarkers. This letter summarizes the consensus of the participants.

Should the currently planned instruments complete their objectives, then we feel that the global reconnaissance mapping of Mars will be completed. The Global Surveyor TES will provide global measurements of Mars using emission spectroscopy (6 - 50 Ám) at 3 km spatial resolution. This will be complemented in 2001 by multispectral visible and thermal infrared imaging at <100 m/pixel (MARCI and THEMIS), and in 2003 by hyperspectral visible and near-infrared imaging (0.4 to 5.0 Ám) at 2 km/pixel (Mars Express OMEGA).

The next instrument should measure spectra of targeted regions to support lander site selection. Mineralogy is an essential tool to assess ancient and modern environments on Mars that may have been conducive to the support and preservation of life and biomarkers. Reflectance and emission spectroscopy remain the most capable method for remote mineral identification. It is likely that the global data sets (TES, THEMIS, MARCI, OMEGA) can be used to identify many potential sites for lander science measurements and sample return. Experience gained from spectral data sets of Mars and Earth has shown that an unambiguous interpretation of a complex region requires spectra with both high spatial resolution and very high information content. Selecting the most desirable landing site will require this type of data set. High information content is obtained by measuring with broad spectral range, high spectral resolution, and most importantly high signal to noise ratio. The data set should not be global, but should focus on the most promising sites identified from the global data sets. The proposed Ariane piggyback micromissions will lack the payload for an instrument capable of making these measurements.

Neither reflectance nor emission spectroscopy alone is sufficient to uniquely determine the full range of minerals that may be present, as each method is sensitive to different physical processes. Together they provide the best capability to identify the surface mineralogy. The broader the spectral range, the less ambiguous the interpretations, and the more technical the justification for selecting a particular landing site.

Interpretation of current and planned data sets will require access by the community to spectral libraries that contain measurements of materials of interest over the full wavelength range of the spacecraft instruments (0.4 - 50 Ám). To facilitate site selection, spectral libraries should be expanded and made available to the community.

On the basis of our extensive experience with laboratory, planetary, and terrestrial spectroscopy, the workshop participants identified the following instrument characteristics required to best select among potential landing sites:

--Spatial resolution of <100 m/pixel.
--Targeted coverage.
--Spectral resolution of <10nm for 0.4 - 2.5 Ám; and lambda / delta-lambda > 250 for 2.5 - 50 Ám.
--Spectra sampled a minimum of 1 to 2 measurements per resolution element (half-Nyquist to Nyquist).
--SNR >500rms for 30% albedo at 2 Ám, and >500 to 1000rms for thermal for 270K.
--As broad a wavelength range as possible.
--High quality calibration.

Such an instrument would provide an essential tool in the phased approach to Mars exploration that NASA has developed. We strongly encourage NASA and the Mars community to consider these recommendations in planning for future missions.

 

Sincerely,

Participants of the workshop, "Spectroscopy of the Martian Surface: What Next?"

Jim Bell

Diane Blaney

Phil Christensen

Ben Clark

Roger Clark

Stéphane Erard

Jack Farmer

William Farrand

Rudy Hanel

Gary Hansen

Kennneth Herr

Eric Keim

Laurel Kirkland

Melissa Lane

Paul Lucey

Richard Morris

Scott Murchie

John Mustard

Carlé Pieters

John Salisbury

Steve Saunders

Allan Treiman

Steve Young

 

 


Recommendations: Supporting Research

 Summary Recommendations: Spectroscopic remote sensing of surface composition has been of critical importance to our current understanding of Mars, as well as other planets. Spectroscopy, especially high resolution spectroscopy, will continue to be of great importance for future Mars exploration and is particularly important for assessing present and past environments in the search for evidence of life. There are two areas that need more emphasis by Research and Analysis Programs: 1) Measurement and public archiving of spectra covering the range 0.4 - 50 Ám; and 2) Testing of quantitative mineral analysis methods. Participants also felt there should be additional discussion of what materials should be measured, and how the data should be archived.

 

Background. On June 10 - 11, 1999 the workshop "Spectroscopy of the Martian Surface: What Next?" was held at the Lunar and Planetary Institute in Houston, TX. At this workshop, leaders of the planetary community with expertise in spectroscopy and remote mineral identification met to discuss the state of understanding of Mars surface composition, and to assess what critical gaps may exist in planned measurements of Mars and supporting research programs. This letter summarizes our consensus about the supporting research programs.

Knowledge of surface composition is an essential tool to assess ancient and modern environments on Mars that may have been conducive to the support and preservation of life and biomarkers. Reflectance and emission spectroscopy are the most capable method for remote compositional mapping. Participants concluded that there remain several critical needs in the ability of the community in order to reliably interpret current and planned spectral data sets. One is the unavailability of supporting spectral libraries that contain diverse measurements over the entire wavelength range measured by current and planned spectrometers (0.4 - 50 Ám). Another is the need to test and compare currently available analytical methods that are used to quantitatively examine remotely sensed spectra.

Laboratory spectra. Two factors are essential for detection and quantification of surface materials: high information content spectra of Mars, and high quality laboratory spectra. Participants concluded that a lack of access by the entire community to measurements over the full wavelength range measured by current and planned spectrometers (0.4 - 50 Ám) seriously impedes interpretations. Measurement of diverse materials relevant to active processes and the environment of Mars over the full wavelength range should be encouraged by current Research and Analysis Programs. This community effort will be strongly aided by insuring that there is a community measurement facility capable of measuring the entire 0.4 - 50 Ám range. It is essential to the success of this integrated approach that spectral data measured under this program are publicly archived, and that the materials measured are well-characterized.

Quantitative methods. Workshop participants concluded that there is a strong need to test and evaluate currently available identification and unmixing algorithms. An important baseline could be established through blind measurements by different algorithm proponents of prepared samples representing increasing degrees of difficulty.

Participants also felt quantitative methods will be advanced by the development of liaisons to similar research programs, such as those developed by Department of Defense and Intelligence agencies. One goal should be to test and incorporate knowledge from these other programs into the NASA community, perhaps by inviting them to participate in the blind measurement program.

Additional discussions. Participants concluded there should be additional public discussion of what materials should be measured, and how the data should be archived. Materials discussed included weathering materials and coatings, and poorly crystalline materials that may be present on Mars. The workshop did not have the goal of addressing these issues, and no consensus was reached, but these issues were felt to be of sufficient importance to warrant further discussion.

Recommendations. Selecting among potential landing sites will be aided by measuring targeted, high information content spectra from orbit, followed by clear, unambiguous interpretations of the spectra. Community access to measurements over the full wavelength range covered by current and planned instruments, and the development and testing of quantitative analysis methods will provide the enabling foundation and data analysis tools that are essential to the phased approach to Mars exploration that NASA has developed. We strongly encourage NASA and the Mars community to consider these recommendations in planning for future research programs.

 

Sincerely,

Participants of the workshop, "Spectroscopy of the Martian Surface: What Next?"

Jim Bell

Phil Christensen

Ben Clark

Roger Clark

Stéphane Erard

Jack Farmer

William Farrand

Rudy Hanel

Gary Hansen

Kennneth Herr

Eric Keim

Laurel Kirkland

Melissa Lane

Paul Lucey

Scott Murchie

John Mustard

Carlé Pieters

John Salisbury

Steve Saunders

Allan Treiman

Steve Young

 


Recommendations: Mars Airplane

Participants felt that with the successful completion of the currently planned remote sensing instruments (TES on Mars Global Surveyor, THEMIS on Mars '01, and OMEGA on Mars Express '03), the next step for Mars surface spectroscopy is targeted imaging spectroscopy at spatial scales < 100 m.

Participants recognized that the Mars Airplane could act as a science and technology demonstration mission, paving the way for the next generation of observation, provided an appropriate instrument was flown at a good location. This instrument would need to have spatial resolution of a few 10's of meters. The instrument should cover a wavelength range at sufficient spectral resolution (l / l D > 250) and signal to noise ratio (>500) to be able to identify specific diagnostic mineral spectral features. High spectral resolution is needed for definitive mineralogic characterization, because the currently planned global survey products will likely be sufficient to identify candidate locations that may contain mineral deposits conducive to preservation of a fossil record. However, a data product capable of prioritizing and characterizing in more detail an interesting site at higher spatial and spectral resolution than is currently planned is of high interest to the community.

While imaging spectroscopy is desirable, a profiling spectrometer taking spectra along the airplane track would also return scientifically useful data, provided it was registered to images. However, a poorly chosen instrument or one flown to a location where the geologic setting would not predict mineralogical variations could be a serious setback in the overall goal of exploring Martian mineralogy at these spatial scales.

 


Participants

James Bell
402 Space Science
Cornell University
Ithaca, NY 14850
email: jimbo@marswatch.tn.cornell.edu
phone: 607-255-5911
fax: 607-255-9002

Diana Blaney
4800 Oak Grove Dr.
M/S 183-501
Pasadena, CA 91109-8099
phone: 818-354-5419
fax: 818-354-0966
email: blaney@kookaburra.jpl.nasa.gov

Philip Christensen
Mail Code 1404
Dept. of Geology
Arizona State University
Tempe, AZ 85287-1404
phone: 602-965-1790
fax: 602-965-8102
email: phil@east.la.asu.edu

Benton Clark
Mail Stop 5-8001
Lockheed Martin Astronautics
PO Box 179
Denver, CO 80201
phone: 303-971-9007
fax: 303-977-3600
email: Benton.C.Clark@lmco.com

Roger Clark
US Geological Survey
P.O. Box 25046, MS 964
Denver, CO 80225
phone: 303-236-1332
email: rclark@speclab.cr.usgs.gov

Stéphane Erard
IAS bât. 121
Université Paris-Sud
F-91405 Orsay, France
email: Erard@ias.fr

Jack Farmer
Mail Code 1404
Dept. of Geology
Arizona State University
Tempe, AZ 85287-1404
phone: 602-965-6748
fax: 602-965-8102
email: jack.farmer@asu.edu

William Farrand
Farr View Consulting
Westminster, CO 80234
phone: 303-450-1128
fax: 303-280-1531
email: farrand@rmi.net
Rudolf A. Hanel
3881 Bridle Pass
Ann Arbor, MI 48108-2264
phone: 734-913-2015

Gary Hansen
University of Hawaii at Manoa
Hawaii Institute of Geophysics and Planetology
School of Ocean and Earth Science and Technology
2525 Correa Road
Honolulu, HI 96822
phone: 808-956-3163
fax: 808-956-6322
email: ghansen@pgd.hawaii.edu

Kenneth Herr
The Aerospace Corporation
Mail Station M5/747
2350 East El Segundo Blvd.
El Segundo, CA 90245-4691
phone: 310-336-5620
fax: 310-336-6524
email: roberta.precious@aero.org

Eric Keim
The Aerospace Corporation
Mail Station M5/747
2350 East El Segundo Blvd.
El Segundo, CA 90245-4691
phone: 310-336-1419
fax: 310-336-1636
email: eric.r.keim@aero.org

Laurel Kirkland
Lunar and Planetary Institute/Rice University
3600 Bay Area Blvd.
Houston, TX 77058-1113
phone: 281-486-2107
fax: 281-486-2162
email: kirkland@lpi.jsc.nasa.gov

Melissa Lane
Lyndon B. Johnson Space Center
NASA, Code SN3
Building: 31, Room 102
2101 NASA Road 1
Houston, TX 77058
email: mlane@ems.jsc.nasa.gov

Paul Lucey
University of Hawaii at Manoa
Hawaii Institute of Geophysics and Planetology
School of Ocean and Earth Science and Technology
2525 Correa Road
Honolulu, HI 96822
phone: 808-956-3137
fax: 808-956-6322
email: lucey@pgd.hawaii.edu

Richard Morris
Lyndon B. Johnson Space Center
NASA, Code SN3
Building: 31, Room 102
2101 NASA Road 1
Houston, TX 77058
phone: 281-483-5040
email: richard.v.morris1@jsc.nasa.gov

Scott Murchie
JHU-APL
John Hopkins Rd.
Laurel, MD 20723-6099
phone: 240-228-6235
fax: 240-228-6670
email: murchie@jhuapl.edu

John F. Mustard 
Department of Geological Sciences
Box 1846
Brown University
Providence, RI 02912
phone: 401-863-1264
fax: 401-863-3978
email: mustard@porter.geo.brown.edu

Carle Pieters
Department of Geological Sciences
Box 1846
Brown University
Providence, RI 02912-1846
phone: 401-863-2417
fax: 401-863-3978
email: Carle_Pieters@.Brown.EDU

John W. Salisbury
84 Cochise Ct.
Palm Coast, FL 32137
phone: 904-446-8457
fax: 904-446-1749
email: salisburys@worldnet.att.net

R. Stephen Saunders
Chief Scientist
Solar System Exploration Office
Space and Earth Science Programs Directorate
Jet Propulsion Laboratory
Mail Stop 180-701
4800 Oak Grove Drive
Pasadena, CA 91109
phone: 818-354-2867
fax: 818-393-0712
email: saunders@jpl.nasa.gov

Allan Treiman
Lunar and Planetary Institute
3600 Bay Area Blvd.
Houston, TX 77058-1113
phone: 281-486-2117
fax: 281-486-2162
email: treiman@lpi.jsc.nasa.gov

Steve Young
The Aerospace Corporation
Mail Station M5/747
2350 East El Segundo Blvd.
El Segundo, CA 90245-4691
fax: 310-336-1636
email: Stephen.J.Young@aero.org

 


Workshop Program

* = presenter

 

Thursday, June 10, 1999

7:45 Registration
8:15 Welcome, Introductory remarks

 

PRESENTATIONS I
8:30 a.m.
Chair: Carlé Pieters

Format: Each talk is 15-20 minutes, followed by a 15-10 minute discussion/questions period.

Mars program + sample return

8:30 Steve Saunders*, Spectroscopy for Mars Exploration

9:00 Jack Farmer*, Environmental and Mineralogical Controls on Fossilization: Key Elements in a Strategy for Mars Exopaleontology

Past/Current data sets

9:30 Jim Bell*, Fifty Years Of Mars Surface and Atmospheric Composition from Telescopes: Highlights and Implications For Spacecraft Studies

10:00 Ken Herr*, 1969 Mariner Mars Infrared Spectrometer (IRS): Lessons for Future Exploration

10:30 BREAK

10:45 Rudy Hanel*, 1971 Mariner Mars Infrared Interferometer Spectrometer (IRIS)

11:15 John Mustard*, Review of the 1989 ISM Instrument and Results

11:45 Phil Christensen*, Mars Surface Mineralogy and Petrology from 1997 MGS TES Data

 

LUNCH
12:15

 

PRESENTATIONS II
1:30 p.m.
Chair: John Salisbury

Format: 15 minute talk + 10 minute questions/discussion. The combined Mini-TES/THEMIS talk is 25 minutes +15 for questions/discussion.

Planned and terrestrial data sets

1:40 Carlé Pieters*, J. F. Mustard, and S. L. Murchie, Aladdin Instruments at Mars

2:05 Phil Christensen*, Overview of the Mini-TES and THEMIS Instruments for the Mars 2001 Surveyor Mission

2:45 Paul Lucey*, A Strategy for Future Mars Spectral Remote Sensing: An Outsider's Opinion

3:10 BREAK

 

 

MODERATED PANEL DISCUSSION
3:25 p.m.
Moderator: John Mustard

Format: Each panelist has a 10 minute talk, and 5 minute questions/discussion. Followed by 60 minute discussion.

3:25 Visible/Near-IR: Roger Clark

3:40 Thermal IR: Phil Christensen

3:55 Both: Jack Salisbury

4:10 "Outside the community" spectroscopist: Paul Lucey

4:25 Surface studies: Ben Clark

4:40 Discussion (60 minutes)

 

 

GROUP DINNER
6:30
The Italian Café

 


Friday, June 10, 1999

PRESENTATIONS III
8:15 a.m.
Chair: Allan Treiman

Format: 15 minute talk, then 10 minute discussion/questions.

8:15 Introductory remarks.

8:25 Diana Blaney* and D. Glenar, In Situ Spectrometers for Martian Mineralogy

8:50 Roger Clark* Mapping the Surface Mineralogy of Hydrothermal Alteration Systems: Applications to the Geologic History of Mars and the Search for Past Life

9:15 William Farrand*, Sub-pixel Detection and Mapping of Spectrally Unique Materials on Mars using ISM Data

9:40 Gary Hansen*, Remote Sensing Spectroscopy of the Polar Regions of Mars

10:05 BREAK

10:20 Eric Keim*, The SEBASS Hyperspectral Imaging Spectrograph: Instrument Description and Sample Thermal Images Obtained Near Flagstaff, Arizona and Mesquite, Nevada (15 minutes + 5 for questions)

10:40 Steve Young*, Use of Thermal Hyperspectral Imagery in Terrestrial Surface Characterization (15 minutes + 5 for questions)

 

LUNCH (brought in)
11:00

 

 

WORKSHOP REPORT MODERATED DISCUSSION
11:45 p.m.
Moderator: Paul Lucey

11:45 Discussion

The discussion will begin with any major issues left unresolved from the panel discussion, and then will address submitted questions.

 

ADJOURN
2:45


 

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