Martian Geology

Martian Geology

TNRTB Archive – Retained for reference information

In a series of 12 peer-reviewed articles the August 6 edition of Science contravenes almost all of the media hype about NASA’s Mars Rovers finding evidence for an abundance of water and chemical evidence for past life. The articles report that instruments on board the Spirit Rover find no evidence to support the claim that Gusev Crater is the site of a former lake, establish that the dominant geologic processes on Mars are physical (meteoritic impact events and dust storms) rather than chemical, determine that the dominant Martian lithology is basalt, and that aqueous alteration of the Martian surface and crust, if it has ever existed at all, was minor and intermittent. The Spirit Rover uncovered more evidence showing that the early, wet episode on Mars 3.8 to 4.0 billion years ago when the late heavy bombardment was delivering huge amounts of cometary ice to Mars was an epoch when sulfuric acid in volcanic emissions would have quickly reacted with water to form sulfate salts. The Spirit Rover also found that the amount of sunlight blocked out by dust in the Martian atmosphere from January to May, 2004 varied from 50 to 90 percent of the Sun’s light. Spirit determined that Martian dust grains vary in size from 0.001 to 3.0 millimeters and that the Martian surface as a result of dust storms is continuously being buried and exhumed by dust layers ranging from 5 to 60 centimeters deep. The bottom line is that planetary scientists now conclude that Mars is far more inhospitable for life than previously thought and Earth is recognized as being much more exquisitely fine-tuned for life than previously thought.