90° W 270° W 30° W 60° W 120° W 150° W 210° W 240° W 300° W 330° W 270° W 90° W 330° W 300° W 240° W 210° W 150° W 120° W 60° W 30° W 150° W 120° W 90°W 60° W 30° W 330° W 300° W 270° W 240° W 210° W 330° W 300° W 270° W 240° W 210° W 150° W 120° W 90° W 60° W 30° W 180° 0° 55° 55° 60° 60° 70° 70° 80° 80° 240° E 210° E 150° E 120° E 90° E 60° E 30° E 330° E 300° E 270° E 180° 0° –55° –55° –60° –60° –70° –70° –80° –80° 270° E 90° E 120° E 150° E 210° E 240° E 300° E 330° E 30° E 60° E 180° 0° 180° 180° 150° E 120° E 90° E 60° E 30° E 0° 150° E 120° E 90° E 60° E 30° E 180° 330° E 300° E 270°E 240° E 210° E 330° E 300° E 270° E 240° E 210° E 57° 50° 30° 0° –30° –50° –57° 57° 50° 30° 0° –30° –50° –57° Stokes Stokes Lomonosov Lomonosov Milankovic Milankovic v ALBA ALBA FOSSAE FOSSAE TANTALUS TANTALUS FOSSAE FOSSAE V A S T I T A S B O R E A L I S V A S T I T A S B O R E A L I S SCANDIA COLLES SCANDIA COLLES Korolev Korolev PLANUM PLANUM BOREUM BOREUM C h a s m a B o r ea l e O L Y M P I A U N D A E * Kunowsky Kunowsky Cydnus Cydnus Rupes Rupes Panchaia Rupes* Panchaia Rupes* S c a n d i a C a vi * Utopia Utopia Rupes* Rupes* Hephaestus Hephaestus Rupes* Rupes* Cydnus Cydnus Rupes Rupes Hyblaeus Dorsa* Hyblaeus Dorsa* Bernard Bernard Columbus Columbus Dejnev Dejnev Newton Newton Mariner Mariner Copernicus Copernicus Ptolemaeus Ptolemaeus Li Fan Li Fan Very Very Liu Hsin Liu Hsin Hussey Hussey Koval'sky Koval'sky Porter Porter Lowell Lowell Fesenkov Fesenkov Sharanov Sharanov Mutch Mutch Vinogradov Vinogradov Holden Holden Hale Hale Hooke Hooke Galle Galle Darwin Darwin Green Green Wirtz Wirtz Helmholtz Helmholtz Arkhangelsky Arkhangelsky Lohse Lohse Vogel Vogel Newcomb Newcomb Galilaei Galilaei Becquerel Becquerel Cassini Cassini Schiaparelli Schiaparelli Flaugergues Flaugergues Bakhuysen Bakhuysen Le Verrier Le Verrier Kaiser Kaiser Proctor Proctor Schaeberle Schaeberle Russell Russell Krishtofovich Krishtofovich Tikhov Tikhov Wallace Wallace Secchi Secchi Arrhenius Arrhenius Kepler Kepler Molesworth Molesworth Graff Graff Campbell Campbell Roddenberry Roddenberry ARCADIA ARCADIA PLANITIA PLANITIA ACIDALIA ACIDALIA PLANITIA PLANITIA CHRYSE CHRYSE PLANITIA PLANITIA LUNAE LUNAE PLANUM PLANUM XANTHE XANTHE TERRA TERRA AMAZONIS AMAZONIS PLANITIA PLANITIA THARSIS THARSIS MONTES MONTES DAEDALIA PLANUM DAEDALIA PLANUM SYRIA SYRIA PLANUM PLANUM SINAI SINAI PLANUM PLANUM SOLIS SOLIS PLANUM PLANUM VALLES VALLES MARINERIS MARINERIS MARGARITIFER MARGARITIFER TERRA TERRA TERRA TERRA SABAEA SABAEA Huygens Huygens ALBA PATERA ALBA PATERA TANTALUS FOSSAE TANTALUS FOSSAE MAREOTIS FOSSAE MAREOTIS FOSSAE TEMPE FOSSAE TEMPE FOSSAE TEMPE TEMPE TERRA TERRA UTOPIA PLANITIA UTOPIA PLANITIA Elysium Elysium Fossae Fossae ARCADIA ARCADIA PLANITIA PLANITIA Albor Albor Tholus Tholus NEPENTHES MENSAE NEPENTHES MENSAE ISIDIS ISIDIS PLANITIA PLANITIA Nili Nili Fossae Fossae SYRTIS MAJOR SYRTIS MAJOR PLANUM PLANUM ARABIA TERRA ARABIA TERRA Aram Aram Chaos Chaos Tharsis Tharsis Tholus Tholus Echus Chasma Echus Chasma Uranius Uranius Patera Patera PAVONIS MONS PAVONIS MONS Ceraunius Fossae Ceraunius Fossae Ulysses Ulysses Patera Patera Biblis Biblis Patera Patera Gordii Dorsum Gordii Dorsum Erebus Montes Erebus Montes ARSIA ARSIA MONS MONS CLARITAS FOSSAE CLARITAS FOSSAE Ius Chasma Ius Chasma Candor Chasma Candor Chasma OPHIR OPHIR PLANUM PLANUM AURORAE AURORAE PLANUM PLANUM Ganges Ganges Capri Chasma Capri Chasma Uzboi Uzboi Vallis Vallis Aureum Aureum Chaos Chaos TYRRHENA TYRRHENA Tyrrhena Tyrrhena Patera Patera HESPERIA HESPERIA PLANUM PLANUM Apollinaris Apollinaris Patera Patera TERRA TERRA CIMMERIA CIMMERIA PROMETHEI PROMETHEI TERRA TERRA Dao Vallis Dao Vallis HELLESPONTUS HELLESPONTUS NOACHIS NOACHIS TERRA TERRA NEREIDUM NEREIDUM CHARITUM MONTES CHARITUM MONTES ARGYRE ARGYRE PLANITIA PLANITIA BOSPOROS BOSPOROS PLANUM PLANUM AONIA AONIA TERRA TERRA Thaumasia Thaumasia Fossae Fossae ICARIA ICARIA PLANUM PLANUM ICARIA FOSSAE ICARIA FOSSAE TERRA TERRA SIRENUM SIRENUM SIRENUM FOSSAE SIRENUM FOSSAE CHARITUM MONTES CHARITUM MONTES MONTES MONTES Chasma Chasma L a b e a t i s F o ss a N O C TI S L A B Y R I N T H US U l y s s e s F o s s a e Clark Clark MONTES MONTES Denning Denning Schroeter Schroeter Dawes Dawes Antoniadi Antoniadi Tikhonravov Tikhonravov NI L O S Y R T I S M E N S A E Baldet Baldet TERRA TERRA ELYSIUM ELYSIUM MONS MONS Herschel Herschel Gale Gale Gusev Gusev Ascuris Ascuris Planum Planum ELYSIUM PLANITIA ELYSIUM PLANITIA THAUMASIA THAUMASIA PLANUM PLANUM L I B Y A M O N T E S T i u Va l l e s S i m ud V a l l i s S h a l b a t a n a V a l l i s M a j a V a l l e s K a s e i V a l l e s E o s C h a s ma A l - Q a h i r a V al l i s H a r m ak h i s V a l l i s R e ul l V a l l i s Ismeniae Ismeniae Fossae Fossae Eumenides Eumenides Dorsum Dorsum T i u V a l l e s Savich Savich Niger Vallis Niger Vallis v Milankovic Milankovic A c h e r o n F o s sa e Diacria Diacria Patera Patera . A L B A F O S S A E Artynia Catena Artynia Catena Cyane Cyane Catena Catena Alba Alba Catena Catena Acheron Catena Acheron Catena P h l e g et hon Ca t e n a Perepelkin Perepelkin Barabashov Barabashov Timoshenko Timoshenko Sytinskaya Sytinskaya Ni l o k e r a s S c o p u l u s Acidalia Acidalia Colles Colles Acidalia Acidalia Mensa Mensa Sklodowska Sklodowska . Cydonia Mensae Cydonia Mensae Semeykin Semeykin . DEUTERONILUS MENSAE DEUTERONILUS MENSAE Mamers Mamers Valles Valles Cerulli Cerulli Focas Focas Moreux Moreux Quenisset Quenisset PROTONILUS MENSAE PROTONILUS MENSAE Rudaux Rudaux Coloe Fossae Coloe Fossae Renaudot Renaudot Colles Colles Nili Nili A u qa k u h V a l l i s Huo Hsing Vallis Huo Hsing Vallis Hrad Hrad Vallis Vallis Viking 2 Viking 2 Landing Site Landing Site Hecates Hecates Tholus Tholus Adams Adams Tyndall Tyndall Stokes Stokes PHLEGRA MONTES PHLEGRA MONTES Marte Vallis Marte Vallis Pettit Pettit Nicholson Nicholson LYCUS LYCUS SULCI SULCI Ol y m p u s R u p e s O l y m p u s R u pe s Gigas Sulci Gigas Sulci Cyane Cyane Sulci Sulci Sulci Sulci Gordii Gordii Olympica Fossae Olympica Fossae Jovis Jovis Tholus Tholus Poynting Poynting Tractus Tractus Fossae Fossae Tractus Catena Tractus Catena Uranius Uranius Tholus Tholus Ceraunius Ceraunius Tholus Tholus ASCRAEUS ASCRAEUS MONS MONS Fortuna Fortuna Fossae Fossae Sacra Mensa Sacra Mensa Sacra Sacra Fossae Fossae Sacra Fossae Sacra Fossae Lunae Lunae Mensa Mensa L o b o V a l l i s B a h r a m V a l l i s Stege Stege Chia Chia . . Nanedi Nanedi Valles Valles Viking 1 Viking 1 Landing Site Landing Site . Da Vinci Da Vinci Ravi Vallis Ravi Vallis . Orson Orson Welles* Welles* A r es V a l l i s Masursky Masursky Sagan Sagan Hydaspis Hydaspis Chaos Chaos McLaughlin McLaughlin M a w r t h V a l l i s Curie Curie Trouvelot Trouvelot Rutherford Rutherford Crommelin Crommelin Radau Radau Marth Marth Maggini Maggini Gill Gill Luzin Luzin Pasteur Pasteur Henry Henry Indus Indus Vallis Vallis Janssen Janssen Teisserenc de Bort Teisserenc de Bort . Flammarion Flammarion Sch Schöner ner . Nili Patera Nili Patera Meroe Patera Meroe Patera . . Arena Arena Colles Colles Peridier Peridier Du Martheray Du Martheray Amenthes Amenthes Fossae Fossae Hephaestus Hephaestus Fossae Fossae Hyblaeus Hyblaeus Fossae Fossae Granicus Granicus Valles Valles Elysium Elysium Chasma Chasma Eddie Eddie Lockyer Lockyer Tartarus Montes Tartarus Montes Tartarus Colles Tartarus Colles Orcus Patera Orcus Patera Hibes Hibes Montes Montes LUCUS LUCUS PLANUM PLANUM Medusae Medusae Fossae Fossae Williams Williams Burton Burton Comas Comas Sola Sola MEMNONIA MEMNONIA FOSSAE FOSSAE Mangala Fossa Mangala Fossa Cobres Cobres M a n g a l a V a l l e s Aganippe Fossa Aganippe Fossa Noctis Noctis Fossae Fossae Oudemans Oudemans Tithoniae Catena Tithoniae Catena Tithonium Chasma Tithonium Chasma Louros Valles Louros Valles Hebes Hebes Chasma Chasma Perrotin Perrotin Ophir Ophir Chasma Chasma Coprates Catena Coprates Catena Lassel Lassel Juventae Juventae Chasma Chasma Solis Solis Dorsa Dorsa Felis Felis Dorsa Dorsa Melas Melas Dorsa Dorsa Ibragimov Ibragimov Nectaris Nectaris Fossae Fossae Ritchey Ritchey Nirgal Vallis Nirgal Vallis . Erythraea Erythraea Fossa Fossa Ladon Ladon Valles Valles Kasimov Kasimov Chekalin Chekalin . Jones Jones Beer Beer Aurorae Aurorae Chaos Chaos Arsinoes Arsinoes Chaos Chaos Pyrrhae Pyrrhae Chaos Chaos Iani Iani Chaos Chaos Margaritifer Margaritifer Chaos Chaos Mädler dler . Wislicenus Wislicenus Pollack Pollack Lambert Lambert Bouguer Bouguer Charybdis Charybdis Scylla Scylla Scopulus Scopulus Scopulus Scopulus Niesten Niesten Oenotria Oenotria Scopulus Scopulus Fournier Fournier Briault Briault Jarry- Jarry- Desloges Desloges Millochau Millochau Ausonia Ausonia Montes Montes Müller ller Knobel Knobel AEOLIS MENSAE AEOLIS MENSAE Wien Wien Lasswitz Lasswitz Hadley Hadley Boeddicker Boeddicker Reuyl Reuyl Ma'adim Ma'ad im de Vaucouleurs de Vaucouleurs . . Magelhaens Magelhaens Hipparchus Hipparchus Eudoxus Eudoxus . Nordenski Nordenski öld ld Kuiper Kuiper Millman Millman Pickering Pickering Brashear Brashear Coblentz Coblentz Slipher Slipher Lampland Lampland Babakin Babakin Douglass Douglass Coracis Coracis Fossae Fossae Ogygis Ogygis Rupes Rupes Bosporos Rupes Bosporos Rupes Halley Halley Oceanidum Oceanidum Mons Mons Bunge Bunge Sumgin Sumgin Bond Bond Bozkir Bozkir Hartwig Hartwig Shatskiy Shatskiy . . Chalcoporos Chalcoporos Rupes Rupes Rabe Rabe Gledhill Gledhill Hadriaca Patera Hadriaca Patera . Teviot Teviot Vallis* Vallis* M o r p h e o s R u p e s Alexey Alexey Tolstoy Tolstoy Haldane Haldane Tycho Tycho Brahe Brahe . Eridania Scopulus Eridania Scopulus Martz Martz Huggins Huggins Bjerknes Bjerknes Cruls Cruls Rossby Rossby Ariadnes Ariadnes Colles Colles Nilokeras Nilokeras Fossae Fossae Kunowsky Kunowsky Nier Nier Vallis Vallis Amazonis Amazonis Mensa* Mensa* Pathfinder Pathfinder Landing Site Landing Site . . . . Airy Airy Isidis Dorsa* Isidis Dorsa* Phlegra Phlegra Dorsa* Dorsa* Xanthe Xanthe Dorsa Dorsa Xanthe Xanthe Dorsa Dorsa . . . . . . Phillips Phillips Maraldi Maraldi Von Karman Von Karman Darwin Darwin Schmidt Schmidt Agassiz Agassiz Chamberlin Chamberlin Stoney Stoney Reynolds Reynolds Charlier Charlier Wright Wright Byrd Byrd Rayleigh Rayleigh Burroughs Burroughs Liais Liais Huxley Huxley Secchi Secchi Gilbert Gilbert Mitchel Mitchel Holmes Holmes Main Main South South Russell Russell CAVI CAVI ANGUSTI ANGUSTI AONIA AONIA TERRA TERRA NOACHIS NOACHIS TERRA TERRA ARGYRE PLANITIA ARGYRE PLANITIA PLANUM PLANUM AUSTRALE AUSTRALE TERRA TERRA SIRENUM SIRENUM TERRA CIMMERIA TERRA CIMMERIA PROMETHEI PROMETHEI TERRA TERRA MALEA MALEA PLANUM PLANUM PLANUM PLANUM CHRONIUM CHRONIUM C H A RI T U M M ON T E S PLANUM PLANUM ANGUSTUM ANGUSTUM Barnard Barnard SISYPHI PLANUM* SISYPHI PLANUM* P R O M E T H E I P L A N U M * A R G E N T E A P L A N U M * Australe Montes* Australe Montes* Sisyphi Cavi Sisyphi Cavi Sisyphi Montes Sisyphi Montes Pityusa Pityusa Patera* Patera* Pityusa Pityusa Rupes Rupes Vishniac Vishniac D o r s a Br e v i a Hutton Hutton Weinbaum Weinbaum Jeans Jeans U l y x i s R u p e s Richardson Richardson Suess Suess Steno Steno Lau Lau Smith Smith Heaviside Heaviside Dorsa Dorsa Argentea Argentea Joly Joly Du Toit Du Toit . Dana Dana Mellish Mellish Lyell Lyell Daly Daly Kuiper Kuiper Trumpler Trumpler Keeler Keeler Clark Clark Dokuchaev Dokuchaev ICARIA ICARIA FOSSAE FOSSAE Lamont Lamont Ross Ross Bianchini Bianchini Coblentz Coblentz AONIA AONIA PLANUM* PLANUM* Fontana Fontana Wegener Wegener Peneus Peneus Patera Patera Malea Malea Patera* Patera* Amphitrites Amphitrites Patera Patera Axius Axius Valles Valles M a d V a l l i s Heinlein Heinlein Wells Wells Eridania Eridani a Scopulus Scopul us Mendel Mendel Chalcoporous Chalcoporous Rupes Rupes A r g y r e R u p es P A R V A P L A N U M * T h yl e s R u p e s P r o m e t h e i R u p e s C h a s m a A u s tral e P r o m e t h e i R u pe s MERIDIANI MERIDIANI PLANUM* PLANUM* Terby Terby Melas Melas Chasma Chasma Coprates Chasma Coprates Chasma HELLAS HELLAS PLANITIA PLANITIA LYOT LYOT Mie Mie Hydraotes Hydraotes Chaos Chaos Alpheus Alpheus Colles Colles Coronae Coronae Scopulus Scopulus OLYMPUS OLYMPUS MONS MONS GEOLOGIC INVESTIGATIONS SERIES I–2782 SHEET 1 OF 2 SCALE 1:25 000 000 (1 mm = 25 km) AT 0° LATITUDE MERCATOR PROJECTION 1000 KILOMETERS 500 0 500 1000 2000 1000 1000 500 500 0 2000 KILOMETERS 0° ±20° ±40° ±57° North South East West 90° 70° 55° 90° 70° 55° 1000 KILOMETERS 500 0 500 1000 –90° –70° –55° –90° –70° –55° INTERIOR —GEOLOGICAL SURVEY, RESTON, VA—2003 Prepared on behalf of the Planetary Geology and Geophysics Pro- gram, Solar System Exploration Division, Office of Space Science, National Aeronautics and Space Administration Manuscript approved for publication December 17, 2002 NOTE TO USERS Users noting errors or omissions are urged to indicate them on the map and to forward it to the Astrogeology Team, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, Arizona 86001. A replacement copy will be returned. Prepared for the NATIONAL AERONAUTICS AND SPACE ADMINISTRATION U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY –8200 Minimum 21229 Maximum Elevations above 9000 meters found only on the larger volcanos Elevation in meters 0 1000 3000 –1000 –3000 –5000 –7000 –9000 5000 7000 9000 11000 13000 15000 17000 19000 21000 SCALE 1:15 196 708 (1 mm = 15.196708 km) AT 90° LATITUDE POLAR STEREOGRAPHIC PROJECTION NORTH POLAR REGION SCALE 1:15 196 708 (1 mm = 15.196708 km) AT 90° LATITUDE POLAR STEREOGRAPHIC PROJECTION SOUTH POLAR REGION Planetographic latitude and west longitude coordinate system is shown in red. Planetocentric latitude and east longitude coordinate system is shown in black. 0° ±20° ±40° ±57° Topographic Map of Mars M 25M RKN By U.S. Geological Survey 2003 Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–800–ASK–USGS Digital files available on World Wide Web at http://geopubs.wr.usgs.gov Printed on recycled paper NOTES ON BASE This map is based on data from the Mars Orbiter Laser Altimeter (MOLA; Smith and others, 2001), an instrument on NASA’s Mars Global Surveyor (MGS) spacecraft (Albee and others, 2001). The image used for the base of this map represents more than 600 million measurements gathered between 1999 and 2001, adjusted for consistency (Neumann and others, 2001, 2003) and converted to planetary radii. These have been converted to elevations above the areoid as determined from a martian gravity field solution GMM-2B (Lemoine and others, 2001), truncated to degree and order 50, and oriented according to current stand- ards (see below). The average accuracy of each point is originally ~100 meters in horizontal position and ~1 meter in radius (Neumann and others, 2001). How- ever, the total elevation uncertainty is at least ±3 m due to the global error in the areoid (±1.8 meters according to Lemoine and others [2001]) and regional uncertainties in its shape (G.A. Neumann, written commun., 2002). The meas- urements were converted into a digital elevation model (DEM; G.A. Neumann, written commun., 2002; Neumann and others, 2001; Smith and others 2001) using Generic Mapping Tools software (Wessel and Smith, 1998), with a resolu- tion of 0.015625 degree per pixel or 64 pixels per degree. In projection, the pix- els are 926.17 meters in size at the equator. Data are very sparse near the two poles (above 87° north and below 87° south latitude) because these areas were sampled by only a few off-nadir altimetry tracks. Gaps between tracks of 1–2 km are common, and some gaps of up to 12 km occur near the equator. DEM points located in these gaps in MOLA data were filled by interpolation. PROJECTION The Mercator projection is used between latitudes ±57°, with a central meridian at 0° and latitude equal to the nominal scale at 0°. The Polar Stereographic pro- jection is used for the regions north of the +55° parallel and south of the –55° parallel with a central meridian set for both at 0°. The adopted equatorial radius is 3396.19 km (Duxbury and others, 2002; Seidelmann and others, 2002). COORDINATE SYSTEM The MOLA data were initially referenced to an internally consistent inertial coordinate system, derived from tracking of the MGS spacecraft. By adopting appropriate values for the orientation of Mars as defined by the International Astronomical Union (IAU) and the International Association of Geodesy (IAG; Seidelmann and others, 2002), these inertial coordinates were converted into the planet-fixed coordinates (longitude and latitude) used on this map. These values include the orientation of the north pole of Mars (including the effects of preces- sion), the rotation rate of Mars, and a value for W 0 of 176.630°, where W 0 is the angle along the equator to the east, between the 0° meridian and the equator’s intersection with the celestial equator at the standard epoch J2000.0 (Seidelmann and others, 2002). This value of W 0 was chosen (Duxbury and others, 2002) in order to place the 0° meridian through the center of the small (~500 m) crater Airy-0, within the crater Airy (Seidelmann and others, 2002; de Vaucouleurs and others, 1973). Longitude increases to the east and latitude is planetocentric as allowed by IAU/IAG standards (Seidelmann and others, 2002) and in accord- ance with current NASA and USGS standards (Duxbury and others, 2002). A secondary grid (printed in red) has been added to the map as a reference to the west longitude/planetographic latitude system that is also allowed by IAU/IAG standards (Seidelmann and others, 2002) and has also been used for Mars. The figure adopted to compute this secondary grid is an oblate spheroid with an equatorial radius of 3396.19 km and a polar radius of 3376.2 km (Duxbury and others, 2002; Seidelmann and others, 2002). MAPPING TECHNIQUES To create the topographic base image, the original DEM produced by the MOLA team in Simple Cylindrical projection with a resolution of 64 pixels per degree was projected into the Mercator and Polar Stereographic pieces. A shaded relief was generated from each DEM with a sun angle of 30° from horizontal and a sun azimuth of 270°, as measured clockwise from north, and a vertical exaggera- tion of 100%. Illumination is from the west, which follows a long-standing USGS tradition for planetary maps. This allows for continuity in the shading between maps and quadrangles, and most closely resembles lighting conditions found on imagery. The DEM values were then mapped to a smooth global color look-up table. Note that the chosen color scheme simply represents elevation changes and is not intended to imply anything about surface characteristics (for example, past or current presence of water or ice). These two files were then merged and scaled to 1:25 million for the Mercator portion and 1:15,196,708 for the two Polar Stereographic portions, with a resolution of 300 dots per inch. The projections have a common scale of 1:13,923,113 at ±56° latitude. NOMENCLATURE Names on this sheet are approved by the IAU and have been applied for features clearly visible at the scale of this map. For a complete list of the IAU-approved nomenclature for Mars, see the Gazetteer of Planetary Nomenclature at http://planetarynames.wr.usgs.gov. Font color was chosen for readability. Names followed by an asterisk are provisionally approved. M 25M RKN Abbreviation for Mars: 1:25,000,000 series, shaded relief (R), with color (K) and nomenclature (N; Greeley and Batson, 1990) REFERENCES Albee, A.L., Arvidson, R.E., Palluconi, Frank, Thorpe, Thomas, 2001, Overview of the Mars Global Surveyor mission: Journal of Geophysical Research, v. 106, no. E10, p. 23,291–23,316. de Vaucouleurs, Gerard, Davies, M.E., and Sturms, F.M., Jr., 1973, Mariner 9 areographic coordinate system, in Journal of Geophysical Research, v. 78, p. 4395–4404. Duxbury, T.C., Kirk, R.L., Archinal, B.A., and Neumann, G.A., 2002, Mars Geodesy/Cartography Working Group recommendations on Mars carto- graphic constants and coordinate systems, in Joint International Symposium on Geospatial Theory, Processing and Applications, Ottawa, Canada, 2002 Commission IV, Working Group 9—Extraterrestrial Mapping, Proceedings: Ottawa, Canada, International Society for Photogrammetry and Remote Sensing [http://www.isprs.org/commission4/proceedings/paper.html]. Greeley, Ronald, and Batson, R.M., 1990, Planetary mapping: Cambridge Uni- versity Press, p. 274–275. Lemoine, F.G., Smith, D.E., Rowlands, D.D., Zuber, M.T., Neumann, G.A., Chinn, D.S., Pavlis, D.E., 2001, An improved solution of the gravity field of Mars (GMM-2B) from Mars Global Surveyor: Journal of Geophysical Research, v. 106, no. E10, p. 23,359–23,376. Neumann, G.A., Rowlands, D.D., Lemoine, F.G., Smith, D.E., and Zuber, M.T., 2001, Crossover analysis of Mars Orbiter Laser Altimeter data: Journal of Geophysical Research, v. 106, no. E10, p. 23,753–23,768. Neumann, G.A., Smith, D.E., and Zuber, M.T., 2003, Two Mars years of clouds observed by the Mars Orbiter Laser Altimeter: Journal of Geophysical Research [in press]. Seidelmann, P.K. (chair), Abalakin, V.K., Bursa, Milan, Davies, M.E., De Bergh, Catherine, Lieske, J.H., Oberst, Juergen, Simon, J.L., Standish, E.M., Stooke, P.J., and Thomas, P.C., 2002, Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites—2000: Celestial Mechanics and Dynamical Astronomy, v. 82, p. 83–110. Smith, D.E., Sjogren, W.L., Tyler, G.L., Balmino, G., Lemoine, F.G., and Kono- pliv, A.S., 1999, The gravity field of Mars—Results from Mars Global Sur- veyor: Science, v. 286, p. 94–96. Smith, D.E., Zuber, M.T., Frey, H.V., Garvin, J.B., Head, J.W., Muhleman, D.O., Pettengill, G.H., Phillips, R.J., Solomon, S.C., Zwally, H.J., Banerdt, W.B., Duxbury, T.C., Golombek, M.P., Lemoine, F.G., Neumann, G.A., Rowlands, D.D., Aharonson, Oded, Ford, P.G., Ivanov, A.B., Johnson, C.L., McGovern, P.J., Abshire, J.B., Afzal, R.S., and Sun, Xiaoli, 2001, Mars Orbiter Laser Altimeter—Experiment summary after the first year of global mapping of Mars: Journal of Geophysical Research, v. 106, no. E10, p. 23,689–23,722. Wessel, Paul, and Smith, W.H.F., 1998, New, improved version of Generic Map- ping Tools released: Eos, Transactions of the American Geophysical Union, v. 79, no. 47, p. 579.