NAVIGATING MARS: ALTITUDE AND LONGITUDE ISSUES

HOME PAGE Web Site Contents Mars Report Contents Mars Report Abstract CV for Dr. David Roffman Diplomas PhD Thesis PhD Thesis Powerpoint Mars PowerPoint MSL Weather Reports Seasonal Pressure Altitude Calculations Seismic Activity on Mars? MSL Year 4 SUMMER Weather MSL Year 4 Spring Weather MSL Yr 3-4 Winter Weather MSL Fall Yr 3 Weather MSL Yr. 3 Summer Weather MSL Yr. 3 Spring Weather Martian plume March 25 2017 MSL Ultraviolet 3 YEARS OF MSL UV Desai, EDL, Parachutes & ExoMars Mars winter vs. summer temps Helo to Mars Sea at Utopia Planitia, Mars Tree Stump at MSL? Spherical life on Mars? Mars Report Abstract, 1-1.2 Mars Report Sec.2-2.1 Report 2.2-2.4 Report 2.5-2.5.2 Report 2.5.3-2.7 Report 3-4 Report 4.1-4.1.2 Report 5 to 6 Report 7-7.2.1 Report 8 Report 9 Report 10 Report 11 Global Dust Storm Report 12 Report 13-13.2 Report 13.3-13.5 Report 13.6 Report 14-15 Report 15.1 Report 15.2-15.3 Report 15.4-15.6.2 Report 15.6.2.1 - 15.6.2.3 Report 15.6.2.4-15.7 Report 16-16.1 Report 17-20 Report References Report Afterword Rebuttal of REMS Report Running water on Mars MSL Year 0 Weather MSL Yr 2 Winter-Spring Weather MSL Yr 2 Summer Weather MSL Yr 2 Fall Weather MSL Yr 2-3 Winter Weather Adiabatics MSL Hi Temps MSL Low Temps Organic Chem found by MSL Oxygen in Mars Air MSL Day length & Temp Warm winter ground temps 155-Mile High Mars Plume Radiation Diurnal Air Temp Variation Mars Temps Fahrenheit Beagle found JPL/NASA Pressure Mistakes Enter MarsCorrect Sol 370, 1160 & 1161 Histories Mars-Radio-Show JPL Fudges Pressure Curves MSL Temp. ∆ Mast to Ground High & Low Pressures Normalized Mars soil 2% water Moving rock Mars MAVEN MSL Relative Humidity Claim Ashima Concedes Original MSL Weather Record Old MSL Weather Record MSL Summer Weather Pressure Estimate REMS Wind MSL Pressures REMS Reports Curiosity Geology CERN-2013-pics Daylight Math MSL Errors P1 MSL Errors P2 MSL-Chute-Flap MSL daylight Ashima Sols 15 to 111 Ashima Sol 112 to 226 Ashima Sol 227 on New Ashima Sols 270+ MSL Summer to Sol 316 Updated Secrets of Mars Weather Forecast Wind Booms MSL Credibility MSL Temp. Swings MSL Temperatures Sample Analysis at Mars (SAM) VL2 - MSL Ls Comparson Ashima MIT Mars GCM Dust Storm Nonsense Mars Slideshow Moving Sand & Martian Wind 3 DEC12 Press Conf. MSL Press Conf. 15NOV2012 Sol Numbering MSL Pressure Graph to Ls 218.8 MSL Sky Color Mars Sky Color DATA DEBATE! Zubrin's Letter Phoenix Vaisala Vaisala Pressure Sensors Phoenix &MSL Flawed MSL REMS Viking pressure sensors failed MSL landing site Mars Landings Phobos Grunt Martian Air Supersaturation Mars & CH4 Mars and MSL Time Viking Pressure Audit Links Mars Society 2008 Quant Finance Frontiers Home Front. Preface Frontiers Ch. 1 Frontiers Ch. 2 Antimatter Lightning Frontiers Ch. 3 Frontiers Ch. 4 Frontiers Ch. 5 Frontiers Ch. 6 Frontiers Ch. 7 Frontiers Ch. 8 Frontiers Ch. 9 Frontiers Ch 10 Frontiers Ch 11 Frontiers Ch 12 Frontiers Ch 13 Frontiers Ch 14 Frontiers Ch 15 Frontiers Ch 16 Frontiers Ch 17 Frontiers Ch 18 Frontiers Ch 19 Frontiers Ch 20 Frontiers Ch 21 Frontiers Ch 22 World Tour Spring-Break -13 Other Travels Asteroid Impact? ExoMars data Unit Issues Viking Pressures Tavis CADs Landing Long Scale Heights LS of Max/Min Pressures Tavis Report Tavis Failures Lander Altitude Martian Trees? Code Experiment Gedanken Report Mars Nuke? Martian Flares Mach Numbers MOLA (altitude) Original Mars Report Mariner 9 & Pressure Mars Temps MSL Time MPF Pressure Blog Debates Spring Pendulum Plasma Model Reporting Errors Orbital Parameters Anderson Localization P. 1 Anderson Localization P. 2 Moving rock old Navigating Mars Mars Report Section Links Mars Report Figure Link Gillespie Lake rock outcrop MSL Sol 200 Anomaly Sol 1300&1301 Anomalies Gilbert Levin & Labeled Release Brine on Mars Ceres Lights Yr 1 Table 1 Missing data Mitchell Report Old Mars Report All MPF Temps ExoMars fails Did Spirit find past life? MSL ground temps go haywire OPACITY AT MSL Luminescence on Mars Dust Storms & Microorganisms 2018 Global Dust Storm Links to Section of the Basic Report

The rules have changed for naming altitudes and longitudes. (Updated 5/14/2014)

Anyone who attempts to seriously crosscheck information about Mars published over the years that we have been sending probes there is likely to get confused because the rules for establishing altitude and longitude have both changed. This article will attempt to clarify the issues involved. Obviously altitudes will greatly affect pressures.

Figure 1 - There are widely different altitudes published for Olympus Mons.

Insert Another Sub Header Here

LONGITUDE SYSTEMS IN USE AND MARS LANDING COORDINATES.

To find specific sites on Mars, you can now use Google Mars. The landing sites for Mars landers are given below; however the topography (MOLA) map included further below appears to use a different coordinate system for denoting longitudes. On Earth longitude coordinates are given from the Prime Meridian (0^O) to 180^O East or West. Phoenix was plotted by this writer, but for Viking 1, Viking 2, and PathFinder (MPF) there are West longitudes in excess of 180^O. In the case of Viking 1 it looks like the 49.97^O West correlates with the plotted longitude of about 310^O (360-49.97^O West).
For MPF, the table given longitude of 33.22^O West correlates well with the plotted value of about 327 (360-33.22^O West). The Google map shows Isidis, which is where the British Beagle was supposed to land, but that probe failed. So the map must have been produced before that failure and the landing of Phoenix that I had to add. This leaves us with one problem, Viking 2. It is plotted at about 135 (East), but the chart lists it as landing at 225.74^O West. However, these longitude positions are basically equal. There are two systems in use for longitudes on Mars:

(1) Planetographic latitude with West longitude. This is the coordinate system originally used in the Gazetteer of Planetary Nomenclature, and the system used for maps produced before approximately 2002. An ellipsoidal equatorial radius of 3,396.0 km and polar radius of 3,376.8 km are assumed.

(2) Planetocentric latitude with East longitude. This is the coordinate system used for maps produced after approximately 2002, although the planetographic latitudes and west longitudes are also shown on printed maps for reference, and the radii on which these are based are different (3,396.19 and 3,376.20 km).

LANDER	DATE LANDED	LATITUDE	LONGITUDE
VIKING 1	JULY 20, 1976	22.48 N (Smith et al. states 22.2692 N)	49.97 W (Smith et al. states 311.8113 E)
VIKING 2	SEP 3, 1976	47.97 N (Smith et al. states 47.6680 N)	225.74 W (Smith et al. states 134.0430 E)
PATHFINDER	JULY 4, 1997	19.13 N (Smith et al. states 19.0949 N)	33.22 W (Smith et al. states 326.5092 E)
SPIRIT at Gusev Crater	JAN 4, 2004	14.5718 S	175.4785 W (Mars globe shows 184.5W, 14.7 S)
OPPORTUNITY	JAN 25, 2004	1.95 S	354.47 E
PHOENIX	MAY 25, 2008	68 N	234 E
MARS SCIENCE LAB	AUG 6, 2012	4.59 S	137.44 E (222.56W)

Smith figures from Smith, D. E., et al. (2001), Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars, J. Geophys. Res., 106, 23,689–23,722, doi:10.1029/2000JE001364. http://www-geodyn.mit.edu/mola.summary.pdf

MARTIAN QUADRANGLES

Name^[4]	Number^[4]	Area^[4]
Mare Boreum (North Pole)	MC-01	Latitude 65° to 90°, Longitude 0° to 360°
Diacria	MC-02	Latitude 30° to 65°, Longitude 120° to 180°
Arcadia	MC-03	Latitude 30° to 65°, Longitude 60° to 120°
Mare Acidalium^[5]	MC-04	Latitude 30° to 65°, Longitude 0° to 60°
Ismenius Lacus	MC-05	Latitude 30° to 65°, Longitude 300° to 360°
Casius^[6]	MC-06	Latitude 30° to 65°, Longitude 240° to 300°
Cebrenia	MC-07	Latitude 30° to 65°, Longitude 180° to 240°
Amazonis	MC-08	Latitude 0° to 30°, Longitude 135° to 180°
Tharsis	MC-09	Latitude 0° to 30°, Longitude 90° to 135°
Lunae Palus	MC-10	Latitude 0° to 30°, Longitude 45° to 90°
Oxia Palus	MC-11	Latitude 0° to 30°, Longitude 0° to 45°
Arabia^[7]	MC-12	Latitude 0° to 30°, Longitude 315° to 360°
Syrtis Major^[8]	MC-13	Latitude 0° to 30°, Longitude 270° to 315°
Amenthes	MC-14	Latitude 0° to 30°, Longitude 225° to 270°
Elysium	MC-15	Latitude 0° to 30°, Longitude 180° to 225°
Memnonia	MC-16	Latitude -30° to 0°, Longitude 135° to 180°
Phoenicis Lacus	MC-17	Latitude -30° to 0°, Longitude 90° to 135°
Coprates	MC-18	Latitude -30° to 0°, Longitude 45° to 90°
Margaritifer Sinus	MC-19	Latitude -30° to 0°, Longitude 0° to 45°
Sinus Sabaeus	MC-20	Latitude -30° to 0°, Longitude 315° to 360°
Iapygia	MC-21	Latitude -30° to 0°, Longitude 270° to 315°
Mare Tyrrhenum	MC-22	Latitude -30° to 0°, Longitude 225° to 270°
Aeolis	MC-23	Latitude -30° to 0°, Longitude 180° to 225°
Phaethontis	MC-24	Latitude -65° to -30°, Longitude 120° to 180°
Thaumasia	MC-25	Latitude -65° to -30°, Longitude 60° to 120°
Argyre	MC-26	Latitude -65° to -30°, Longitude 0° to 60°
Noachis^[9]	MC-27	Latitude -65° to -30°, Longitude 300° to 360°
Hellas	MC-28	Latitude -65° to -30°, Longitude 240° to 300°
Eridania	MC-29	Latitude -65° to -30°, Longitude 180° to 240°
Mare Australe (South Pole)	MC-30	Latitude -90° to -65°, Longitude 0° to 360°

The Relationship of the MOLA Topography of Mars to the Mean Atmospheric Pressure

Internet Source: http://adsabs.harvard.edu/abs/1999DPS....31.6702S

Smith, D. E.; Zuber, M. T. American Astronomical Society, DPS meeting #31, #67.02

The MOLA topography of Mars is based on a new mean radius of the planet and new equipotential surface for the areoid. The mean atmospheric pressure surface of 6.1mbars that has been used in the past as a reference level for topography does not apply to the zero level of MOLA elevations. The MOLA mean radius of the planet is 3,389,508 meters and the mean equatorial radius is 3,396,000 meters (Zuber incorrectly gives it as 339,600 meters). The areoid of the zero level of the MOLA altimetry is defined to be the potential surface with the same potential as the mean equatorial radius. The MOLA topography differs from the USGS digital elevation data by approximately 1.6 km, with MOLA higher. The average pressure on the MOLA reference surface for Ls =0 is approximately 5.1 mbars and has been derived from occultation data obtained from the tracking of Viking, Mariner, and MGS spacecraft and interpolated with the aid of the Ames Mars GCM. The new topography and the new occultation data are providing a more reliable relationship between elevation and surface pressure.