Mars once rained water, according to California study

William Atkins
Thursday, 26 June 2008 19:52

Science - Space

According to research led by University of California--Berkeley geoscientists, the atmosphere of ancient Mars once held enough liquid water for a light drizzle or dew to fall onto the surface of the planet.

The conclusion of the study goes against the general opinions that most planetary scientists hold as to the direction liquid water once flowed on Mars.

Most views hold that, if liquid water ever existed in the Martian past, it probably came from groundwater beneath the surface, rather than rain from above it.

The view of this UCB study is that water of ancient Mars probably flowed like it does on Earth today, primarily downward in the form of rain.

Led author in the study, Ronald Amundson, from the Department of Environmental Science, Policy and Management, UC-Berkeley, states, “By analyzing the chemistry of the planet's soil, we can derive important information about Mars' climate history. The dominant view, put forward by many now working on the Mars missions, is that the chemistry of Mars soils is a mix of dust and rock that has accumulated over the eons, combined with impacts of upwelling groundwater, which is almost the exact opposite of any common process that forms soil on Earth."

Amundson adds, "In this paper, we try to steer the discussion back by re-evaluating the Mars data using geological and hydrological principles that exist on Earth." [UC Berkeley News: “Martian air once had moisture, new soil analysis says”]

The results of their research is contained in the article “On the In Situ Aqueous Alteration of Soils on Mars,” which was published online May 21, 2008, by the journal Geochimica et Cosmochimica Acta, which is a publication of the International Geochemical Society.

The researchers for the study are Ronald Amundson, Stephanie Ewing, William Dietrich, Brad Sutter, Justine Owen, Oliver Chadwick, Kunihiko Nishiizumi, Michelle Walvoord and Christopher McKay.

The researchers--from the University of California, NASA Johnson Space Center (Houston, Texas), U.S. Geological Survey (Lakewood, Colorado), and NASA Ames Research Center (Moffitt Field, California)--used historic data from past NASA missions; specifically, Viking 1 and Viking 2, Pathfinder, and the twin rovers Spirit and Opportunity from Mars Exploration Rovers.

The published data from these mission provided soil data taken between 1976 and 2006 from various sites throughout Mars’ surface. They found from their research that soil on Mars had lost some of its elements from its rock fragments.

Amundson and his team make conclusions that are discussed on the next page. Please read on.