Is the Geography on Mars Similar to the Geography on Earth?

Is the Geography on Mars Similar to the Geography on Earth?

Gale Crater on Mars Shows Detailed Record of Planet’s History, Much Like Craters on Earth Do

March 2010 National Scene Magazine Space Article

Written by: Karen Benardello


The layers in a Mars crater the size of Connecticut shows a detailed record of the planet’s history and major environmental changes from a billion years ago, NASA announced on February 11. The layers of the Gale Crater show the dominant planet-wide pattern for early Mars, according to a new report from the Mars Reconnaissance Orbiter.

Scientists have long been looking at Earth’s rocks and geological layers to understand stages in the evolution of its climate, and decided to do the same for Mars. The Reconnaissance Orbiter report shows that “This thick sequence of rocks appears to be showing different steps in the drying-out of Mars,” Ralph Milliken of NASA’s Jet Propulsion Laboratory in Pasadena, California said of the discovery.

Milliken wrote a report with two co-authors in Geophysical Research Letters, and stated that clay minerals, which form under very wet conditions, are concentrated in layers near the bottom of the Gale crater. In the middle are sulfate minerals, which can be deposited when the water in which they are dissolved evaporates. At the top of the crater are layers that bear no detectable water-related minerals.

Other craters have been discovered with rock exposures on Mars. However, the Gale is the first to show a single series of layers with clay-producing conditions followed by sulfate-producing conditions followed by dry conditions in a sequence of older rocks to younger rocks.

Evidently, NASA made the right decision when it chose the Gale Crater in 2008 as one of four finalist sites for the Mars Science Laboratory rover, Curiosity. Since a crater has finally been discovered on Mars showing similar physical characteristics as those on Earth, NASA scientists will finally have the evidence they need to support looking for life forms on the red planet.