CHEMICAL & ENGINEERING
M i t ΤΙ LΓΤΕi t lA/uPLc IM t\A/Q ΕΙΠί Ο fOit VVttrx MARCH 8, 2004 - EDITED BY WILLIAM
PLANETARY
EXPLORATION
MARS WAS WET Results from rover Opportunity show almost unequivocal signs of water
S
CIENTISTS ANNOUNCED ON
March 2 the stunning discovery that martian rocks examined by the rover Opportunity were once "soaked inliquid water." Steven W Squyres, astronomy professor at Cornell University and head of the science team for Opportunity and its companion rover, Spirit, told reporters at the National Aeronautics & Space Administration's headquarters in Washington, D.C., that numerous lines of evidence point nearly unequivocally to large amounts of water on Mars. "That
through" with flat holes about a centimeter long and a rnillimeter wide, Squyres said. "It was as if a bunch of objects the size and shape ofpennies were embedded and went away," he said. Similar structures on Earth are formed when minerals dissolved in water seep through and precipitate inside rock. Eventually, the crystals dissolve or are eroded away, leaving tabular holes. And curious spherules—dubbed "blueberries" by scientists—
SCHULZ
JANETS DODD
T h e salt concentration in Guadalupe may be as high as 40%, Benton C. Clark III, rover scientist and chief scientist of space exploration at Lockheed Martin Space Systems Astronautics Operations in Denver, said at the briefing. "This is an astounding amount of salt," Clark said. 'This can no longer be considered a volcanic outcrop of some kind. The only way you can form such a large concentration of salt is to have water." The rover's Môssbauer spectrometer also found evidence of jarosite, a hydrated iron sulfate, in the outcropping. Jarosite, which needs water to be created, is a rare mineral also found on Earth. The results should give
Squyres
WATERLOGGED
doesn't mean life was there, but Mars was a habitable place at one time," he said. Whether the rocks were laid down in a briny sea or deposited by water percolating to the martian surface is still unknown, but rover team scientists intend to answer that question in a week or two. For the past three weeks, Opportunity has used its instruments to examine an outcropping of rock inside the small crater in which it landed. A section of the rock known as El Capitan is "shot HTTP://WWW.CEN-ONLINE.ORG
embedded within the rocks likely were deposited by water. Previously, Opportunity had detected a high concentration of sulfur on the rock's surface, in particular, on a section of the outcropping called Guadalupe. The rover then used a grinding tool to expose rock underneath, where its α-particle X-ray spectrometer also found extraordinarily high lev els of the element. The only ex planation, the scientists said, is that the rock is composed largely of sulfate salts, a telltale sign ofliq uid water.
impetus to the de velopment of future Mars mis sions, in particular, plans to return samples to Earth, said James B. Garvin, NASAs lead scientist for Mars and lunar exploration. "What an amazing time to be alive doing science on Mars," he said. "The President gave us a chal lenge to go explore, and here we are, exploring." Meanwhile, halfway across the Red Planet, the rover Spirit con tinued grinding away at a rock named Humphrey Spirit is grad ually heading toward the rim of a crater named Bonneville, where it will examine the terrain inside.-ELIZABETH WILSON
Mars rover | Opportunity's examination of the outcropping nicknamed El Capitan shows evidence of waterdeposited sulfate salts.
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