Mars Astrobiology: Recent Status and Progress - Planetary Exploration and Science: Recent Results and Advances - page 171

Fig. 8.12 Millimetric-scale gullies within sand ridges at a beach on Earth, resembling meter-to-
kilometric-scale gullies on Mars. This shows interesting geochemical-physical similarities between
the two planets and, also, the scale-invariance property of fractal geometry embedded within such
geological processes (Photograph by the author: de Morais 2009)

was lost before reaching closer to Mars. With Mars 2 and Mars 3 in 1971-1972,
information was obtained on the nature of the surface rocks and altitude profiles
of the surface density of the soil, its thermal conductivity, and thermal anomalies
detected on the surface of Mars. The missions found that its northern polar cap has
a temperature below 110 ı C and that the water vapor content in the atmosphere of
Mars is 5,000 times less than on Earth. No signs of life were found.

8.3.9.2 Mariner 4

Mariner 4 probe performed the first successful flyby of planet Mars, returning the
first pictures of the Martian surface in 1965. The photographs showed an arid Mars
without rivers, oceans, or any signs of life. Further, it revealed that the surface
(at least the parts that it photographed) was covered with craters, indicating a lack
of plate tectonics and weathering of any kind for the last 4 billion years. The
probe also found that Mars has no global magnetic field that would protect the