Mars Dunes - Dune Worlds: How Windblown Sand Shapes Planetary Landscapes - page 130

Fig. 12.3 This spectacular picture of the Martian landscape by the
Viking 1 lander shows aeolian features remarkably similar to many
seen in the deserts of Earth. The dramatic early morning lighting—
7:30 a.m. local Mars time, on August 3, 1976—reveals subtle details
and shading. The picture covers 100 of azimuth, looking northeast at
left (where the large rock was nicknamed 'Big Joe') and southeast at
right. The sharp dune crests indicate the most recent winds capable of
moving sand in the general direction from upper left to lower right.

Small deposits downwind of rocks also indicate this wind direction.
Large boulder at left is about 8 m from the spacecraft and measures
about 1 9 3 m. The meteorology boom, which supports Viking's
weather station, cuts through the picture's center. The sun rose two
hours earlier and is about 30 above the horizon near the center of the
picture. (For a similar view at Viking 2, showing changes over several
years, see Fig. 16.14 ) Credit NASA PIA00393

Fig. 12.4 Locations of landers and rovers (squares) and example
dune fields (circles), on TES albedo superposed on MOLA shaded
relief. The spacecraft are V1,V2—Viking Landers 1 & 2; MP—Mars
Pathfinder; Sp, Op—Mars Exploration Rovers Spirit and Opportunity;

Ph—Mars Phoenix; Cu—The Mars Science Laboratory Curiosity.
NASA/JPL/ASU, www.mars.asu.edu/data/tes_albedo , annotated by J.
Zimbelman

• the Mars Global Surveyor observed the planet from orbit
using multiple instruments for more than a decade;
• the Mars Odyssey and Mars Express orbiters brought
even more powerful spectrometers and cameras to Mars;
• the twin Mars Exploration Rovers explored tens of kilo-
meters

• the Mars Reconnaissance Orbiter still continues to operate
the best camera and spectrometer yet flown to Mars; and
• the Curiosity rover has only barely begun its mission to
look for organic materials in sediments within the Gale
crater (see a map of the various landing sites and major
dune fields in Fig. 12.4 ).
Today there is a staggering wealth of spacecraft data
available for Mars, with the in situ information at several
locations (see also Chap. 16 ) supplemented by images from

across Mars, far exceeding their design

requirements;
• the Phoenix lander sampled ground ice only a few centi-
meters below the surface at high northern polar latitudes;