FALSE COLOR RELIEF MAP OF MARS
with landing locations of US and Soviet/Russian probes
numbers next to the crosshairs correspond to list below
The "Forward, On to Mars!" chapter in our Russians in Space CD-ROM begins with the phrase, "The legendary reluctance of the planet Mars to give up its secrets...". That legend, which continues to this day, has a strong basis in fact as you can see below. Isn't it curious that missions to Venus, a much harsher environment, have been much more successful?
Missions to the Red Planet, in order :
plus nation, launch date, result (bold = success)

  • 1. Mars 1M#1 - USSR 10 October 1960. Launch failure (Molniya).
  • 2. Mars 1M#2 - USSR 14 October 1960. Launch failure (Molniya).
  • 3. Sputnik 22 - USSR 24 October 1962. Upper stage? (Molniya) exploded in earth orbit 29Oct1962, probe reentered 29Oct1962.
  • 4. Mars 1 - USSR 01 November 1962. Contact lost enroute to Mars.
  • 5. Sputnik 24 - USSR 04 November 1962. Failed to make earth orbit (Molniya), reentered 05Nov1962.
  • 6. Mariner 3 - USA 05 November 1964. Shroud failure prevented data return during flyby.
  • 7. Mariner 4 - USA 28 November 1964. Returned pictures during flyby, telemetry ended 20Dec1967.
  • 8. Zond 2 - USSR 30 November 1964. Contact lost enroute to Mars.
  • 9. Mariner 6 - USA 24 February 1969. Returned flyby pictures 31Jul1969.
  • 10. M-69 #521 - USSR 27 March 1969. 2nd stage (Proton) failure.
  • 11. Mariner 7 - USA 27 March 1969. Returned flyby pictures 05Aug1969.
  • 12. M-69 #522 - USSR 02 April 1969. 1st stage (Proton) failure.
  • 13. Mariner 8 - USA 09 May 1971. 2nd stage (Atlas-Centaur) failure resulted in ocean-synchronous (Atlantic Ocean) orbit.
  • 14. M-71 #170 (aka Kosmos 419) - USSR 10 May 1971. 3rd/4th stage (Proton) separation failure in earth orbit, reentered 12May1971.
  • 15. Mars 2 - USSR 19 May 1971. Orbiter: entered 1380 km X 25000 km X 49 deg. Martian orbit on 27Nov1971, returned data for months;
    Lander: crashed 27Nov1971? at 44 South x 211 West northwest of Kepler Crater.
  • 16. Mars 3 - USSR 28 May 1971. Orbiter: entered 1530 km X 214500 km X 60 deg. Martian orbit on 2Dec1971, returned data for months,
    Lander: landed 2Dec1971? at 45 South x 158 West near Ptolemaeus Crater, failed shortly after (20 min.?).
  • 17. Mariner 9 - USA 30 May 1971. Entered 1394 km x 17144 km x 64 deg. Martian orbit on 13Nov1971, returned many pictures.
  • 18. Mars 4 - USSR 21 July 1973. Failed to orbit Mars, returned pictures during flyby 10Feb1974.
  • 19. Mars 5 (aka M-73 #52S) - USSR 25 July 1973. Entered 1769 km X 32560 km X 35 deg. Martian orbit on 12Feb1974, failed shortly thereafter, returned some pictures and other data.
  • 20. Mars 6 - USSR 05 August 1973. Flyby bus in solar orbit;
    Lander returned data during descent, failed before landing 12Mar1974 at 23 South x 25 West south of Margaritifer Sinus.
  • 21. Mars 7 - USSR 09 August 1973. Flyby bus in solar orbit;
    Lander missed Mars when?
  • 22. Viking 1 - USA 20 August 1975. Orbited Mars 19Jun1976, died 07Aug1980, reentered 19Nov1985;
    Lander set down 20Jul76 at 22 North x 49 West in Chryse Planitia, died 01?Nov80, both very successful.
  • 23. Viking 2 - USA 09 September 1975. Orbited Mars 07Aug1976, died 24Jul1980, reentered when?;
    Lander set down at 03Sep76 at 46 North x 223 West in Utopia Planitia, died 12Apr1978; both very successful.
  • 24. Fobos 1 (aka 1F #101) - USSR 07 July 1988. Contact lost 29Aug1988 enroute to Martian moon Phobos due to controller error , flew past Mars.
  • 25. Fobos 2 (aka 1F #102) - USSR 12 July 1988. Orbiter and ADU penetrator entered 6145 km X 6409 km X 1.3 deg. Mars orbit on 31Jan1989, contact lost 18Feb1989 due to controller error?, some data returned.
  • 26. Mars Observer - USA 25 September 1992. Contact lost, exploded? at Mars orbit insertion burn 21Aug1993, flew past Mars.
  • 27. Mars Global Surveyor - USA 07 November 1996. Entered Mars polar sunsyn orbit 12Sep1997, mapping delayed till 01?Nov1998, currently working.
  • 28. Mars '96 - Russia/Int'l 16 November 1996. Upper stage failure in earth orbit (Proton/Blok DM); orbiter, lander and upper stage reentered within one orbit; sleeps with the fishes (Pacific Ocean) or with the llamas (crashed in Bolivia)?
  • 29. Mars Pathfinder - USA 04 December 1996. Landed on Mars 04Jul1997 at 19 North by 33 West near mouth of Ares Vallis, returned pictures and data, died 01?Nov?1997;
    Sojourner rover worked, traversed 100? meters, died 01?Nov1997
  • 30. Mars Climate Observer - USA 11 December 1998. Burned up in Martian atmosphere due to navigation error 23Sep1999.
  • 31. Mars Polar Lander USA - 03 January 1999. Contact lost 03Dec1999, apparently failed during reentry or landing;
    Amundsen, Scott penetrators also failed to separate from bus? The large and small crosses in the southern hemisphere mark the intended touchdown coordinates: 76 South x 195 West for lander, 75 South x 196 West for penetrators. The tick marks define the upper and lower boundary of the landing ellipse.
Credit goes out to TRW Space Log 1957-1996, The Planetary Report published by The Planetary Society, Jonathan's Space Report, Proton Mission Planner's Manual, and Chris Jones: clj@world.std.com.
  • For reference, the Martian moon Phobos is in a 5836 km X 6117 km X 1.1 degree orbit, while the other moon Deimos is in a 20108 km X 20146 km X 2 degree orbit.
Notes about the new maps from NASA's Mars Global Surveyor probe
In late May, NASA's Jet Propulsion Lab released the impressive mapping results from Mars Global Surveyor to the press, coincident with the publication of an article in Science. I have modified JPL's false-color topographic map to reflect a more intuitive layout (IMHO; granted the former layout was more compact). The false color scale off to the left shows the corresponding elevation. The datum, defined as 0 km, is light yellow-green.
The prime meridian runs straight down the center of all three sections of the map. The equator runs from left to right across the rectangular portion, which extends to the 70th parallels north and south. The longitude convention on Mars is 0-360 degrees, instead of the 0-180 East or West convention as used on Earth. It is over 21,300 km wide at the equator; but only about one third that, 7300 km, at the 70th parallels due to the unavoidable distortion when rendering a spherical map onto a flat surface. Imagine curling the central part into a ring so the left and right edges meet. Then fold over the two ends, capping the tube so all the coordinates line up. Topologically, you have a cylinder masquerading as a sphere. Each tick mark on the scale around the rectangular portion equals 5 degrees latitude or longitude. Note how the latitudinal ticks stretch farther from the equator to compensate for distortion.
Meanwhile, the north and south polar projections also extend to the 70th parallels. The top and bottom circular sections have a diameter of 2400 km. The gray circle at the south pole is an image artifact.
Here are some features which I found noteworthy:
  • Hellas Planitia (the deep blue circle centered at 45 S x 70, which was misnamed "plain", but is now known to be an impact basin) dominates the topography of Mars, even more so than the Tharsis Bulge (gray and white areas near the equator from 230 to 270). Note the raised annular feature roughly 10,000-12,000 km in diameter surrounding Hellas. That impact must have been truly awesome, probably visible across the solar system. See the analysis below. The famous Valles Marineris, the canyon system which would stretch across the entire United States, is almost lost in this image (it's the light blue horizontal streak from 260 to 320 at the equator). The northern walls of Hellas appear to be almost vertical - imagine what the view would be like from a sheer cliff 7-9 km high! The floor of the basin is by far the deepest place on the planet's surface.
  • There is a much wider, yet much shallower basin in the northern hemisphere centered about 45 degrees North by 120 degrees East - the lip approaches the northwest slope of Elysium Mons.
  • Something has resurfaced the entire northern hemisphere (Vastitas Borealis) recently (only 2-3 billion years ago instead of 4 billion), as it almost completely lacks large craters like the rest of Mars. The Northern Waste may actually be an impact basin (but some planetary scientists think not), subsequently refilled with lava like the lunar maria, as it is smoother and on average 4 km lower than the rest of Mars. Thus, the entire southern hemisphere may just be the ejecta blanket from the massive boreal impact. If so, Mar's inventory of volatiles (C, H, N) may have been largely cooked off into space. The planet's axis of rotation probably shifted to where it is now as a result of the mass redistribution.
  • Argyre Planitia (another misnomer) is about 4 km shallower than Hellas Basin, even though they appear comparable on a gray scale flat map. There seems to have been another Argyre-sized basin between the two, but it has been nearly erased by subsequent bombardment.
  • The true height of Olympus Mons and the other Tharsis volcanoes (Arsia, Pavonis, Ascraeus) is not fully displayed by the scale bar at left. They all top 27 km above the datum (however that datum has certainly been readjusted in light of the new laser altimeter readings). Why all the same height, even though the diameters are different? Probably because 27 km is the structural limit of the local basaltic rocks in martian gravity. At that point, they can't get any higher, they just spread out plastically.
  • If Mars had about 100 times as much water as it seems to, then the boundaries of its oceans and seas would correspond to the blue contours you see. If Mars were fully terraformed, the northern hemisphere would have a cool, wet oceanic climate; the southern hemisphere would be cold, dry and alpine. Except for Hellas, which might actually get warm at the bottom.
  • The southern climate is more extreme than the northern because Mar's orbital eccentricity, which is greater than Earth's, acts in phase with its axial tilt, which is also greater. (On Earth, they are not only out of phase, but climate is moderated by the thermal inertia of huge reservoirs of liquid water, i.e., oceans.) In Mar's boreal region, water freezes. But during austral winter, the air itself freezes. The south polar cap of dry ice (frozen CO2) extends almost to 60 degrees latitude, while the northern cap is much less variable. There are impressive canyons at both poles.
  • Nevertheless, don't be too impressed by this seemingly rugged terrain - if Mars were the size of a billiard ball, it would still be almost as smooth. Actually, the best way to grasp the scale of the landforms on Mars in relation to the whole planet is to imagine a large orange - the surface variation of its pebbled rind is about one percent of the radius of the fruit itself.
Analysis

The revised description of the Hellas impact basin in the Southern Hemisphere impelled me to do some of those back o' the envelope calculations which I so dearly love.
NASA said that Hellas basin is 2100 km diameter and 9 km deep, and that the ejecta blanket is 2 km thick at the crater's rim, and extends out 4000 km from ground zero. (By comparison, the most recent printed map, available from the Planetary Society, which was based on Viking and Mariner data, says Hellas is 5-6 km deep at most.) This is also at least twice the depth as described in Kim Stanley Robinson's Red/Green/Blue Mars trilogy.
Assuming as a first approximation that the thickness of the debris falls off linearly with distance (in fact it falls off more steeply than that, parabolically), then the total volume of the ejecta can be approximated by an annular cone 2 km high x 4000 km radius with a hole of 1050 km radius. Vol = (pi* (Ro^2 - Ri^2) * t)/3 = 32 million cubic km (roughly).
Now the crater can be approximated by a very low cylinder (think of the proportions of a dime) because the thickness of the ejecta layer which fell back inside the crater is at least as thick as the ejecta layer at the rim. Thus it's volume is Vol = (pi * R^2 * h) = 31 million cubic km (roughly), within 3% of the first figure.
Conclusion? It was reasonable for NASA to say that Hellas ejecta from the Hellas Impact is an important component of the overall topography of the Martian Southern Highlands.
Scaling from Chixulub crater on Earth (site of the K-T impact which killed off the dinosaurs), and allowing for Mar's shallower gravity well and lighter material, I estimate that the Hellas impactor was at least 140 km in diameter.
Ain't physics fun?
WHAT'S COMING NEXT: The icons showing of the Soviet and American martian probes on the map above will be interactive soon. Your comments are welcome: robot@ultimax.com

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These pages last updated December 7, 1999