In the space of the entire universe, the only conclusive evidence of life, is found on Earth.
Although the ultimate source of all life is unknown, many investigators believe Earth, Mars …

The debate over the early Martian climate is among the most intriguing in planetary science.
Although the geologic evidence generally supports a warmer and wetter climate, climate …

Various landforms suggest the past presence of liquid water on the surface of Mars. The
putative coastal landforms, outflow channels and the hemisphere-wide Vastitas Borealis …

Mars has been subject to repeated waxing and waning episodes of extreme chaotic
obliquity (axial tilting) for at least four billion years. Obliquity is currently at 25.19 degrees …

Abstract In 1976, NASA's Viking 1 Lander (V1L) was the first spacecraft to operate
successfully on the Martian surface. The V1L landed near the terminus of an enormous …

Deltas have long been considered a constraining element to reconstruct the water level of
an ancient ocean that may have once occupied the northern lowlands of Mars, and recently …

There is widespread evidence across Mars of past flows in major channel systems as well
as more than one palaeo ocean level. However, evidence for the timing of channel flows …

Billions of years ago, the Northern Hemisphere of Mars may have been covered by at least
one ocean and thousands of lakes and rivers. These findings, based initially on telescopic …

Vesicular rocks and thick clumps of green-colored matter photographed in Utopia Planitia
and Chryse Planitia by NASA's Viking landers were subject to morphological and …

Bedrock erosion and canyon formation during extreme floods have dramatically altered
landscapes on Earth and Mars. Grand Coulee was carved by outburst floods from …