“Cross-bedded” silicon dioxide layers in Gale Crater. Credit: NASA/JPL-Caltech/Malin Space Science Systems
Apr 19, 2016
Earth should not be used to explain the Solar System.
Previous Pictures of the Day discuss dune-like formations in various locales, except they are seen on other celestial bodies, such as Saturn’s planet-sized moon, Titan.
Along with the extraterrestrial example, Australia’s Simpson desert contains 1240 parallel, unmoving “string dunes” that run for over 300 kilometers. They are not typical aeolian features, because they appear to be unaffected by the hot winds that frequently blow through the region—they do not travel. They are also associated with deep striations that are not easily explained through conventional geology, unless it is assumed that some processes occurred in the past that are no longer as active today.
It is possible that the dunes and the gullies are old enough that they correspond to the last interglacial periods when flowing water is supposed to have eroded Australia. However, they do not have the appearance of great age. The dunes, especially, appear to be young. Appearances alone are not sufficient evidence for any theory. Although, exposure to the elements for tens of thousands of years should have etched some signs of antiquity into them, yet they look like they are new.
Recent images from the Mars Science Laboratory, otherwise known as the Curiosity Rover, are suggestive of sedimentary layering and “crossbedding“ that also suggest petrified dunes. Martian areologists claim that the slabs of rock they observe are similar to dunes on Earth.
The surface of Mars is largely composed of iron and silicon, with massive quantities of oxygen bound into the soils and bedrock. It is like Earth in some respects, except that the crust is low in aluminum, which is common on Earth. Also, the atmosphere on Mars is so thin—sometimes described as standing on top of a mountain six-times higher than Everest—it lacks the ability to aggressively attack the Martian lithosphere.
On Earth, water vapor in the atmosphere forms a weak carbonic acid solution when it mixes with carbon dioxide and that helps to wear away the rocks. On Mars, such erosion is impossible for several obvious reasons, not the least of which is that there is no open water on Mars or in its atmosphere.
The presence of iron oxide in several different forms causes some investigators to conclude that there once was an oxygen-rich atmosphere on Mars that allowed its iron crust to “rust”, thus creating the enormous quantities of powdered hematite and magnetite. As the overall theory goes, the planet must have gone through a stage when there were oceanic quantities of liquid water on the surface. Modern science has retained the long-hoped-for desire that Mars could be the cradle of different life forms that arose and evolved in a separate ecology. Indeed, that is Curiosity’s primary mission, the search for life.
However, there is disagreement about whether any appreciable water could ever have existed on Mars. On March 5, 2007 Scientific American reported that most of what has been interpreted as water-based erosion on Mars could have come from “dry avalanches” of dirt. The authors expressed serious doubts about whether observations demonstrate any effects caused by liquid water.
The striated and layered rock in the above image is sharp-edged and broken into angular polygons. The fissures running through the area are filled with pebbles and fine dust. Close up images of the layered chunks reveal some of them to be razor-thin. Similar structures were observed by the Opportunity Rover, still alive and rolling through the Martian terrain.
Those formations exhibit fractures that radiate in concentric arcs from what appear to be hollow impact zones, and have been roughly etched, or eroded away on top. The cracks have edges that are also sometimes razor-sharp. Several seem to be sliced off from large blocks composed of the same material. They cannot be the result of water erosion or deposition.
Since the formations on Mars are thought to be extremely old and cut by water millions of years ago, they are considered to be the result of activity that occurs on Earth in the present. Therefore, Earth-based geology is used to explain Martian areology. Electricity is never part of the equation. Failing to consider it, NASA scientists miss vital clues in their search for answers to the puzzles of planetary scarring and the origin of Martian surface features.
Stephen Smith
