Signs of ancient hydrothermal vents found on Mars

May 22, 2008 The Spirit Rover, one of two planetary rovers operated by NASA on the planet Mars, has made an important, though unintentional discovery on the red planet, due to a wheel which has been inoperable on the rover making large gouges in the soil of Mars wherever it goes.

Scientists say they can confirm that images from the planet taken in May of 2007 at Gusev Crater, show that a white substance in the soil that was turned up as the rover moved along its path is Silicon dioxide or silica. Scientists at Cornell University in Ithaca, New York who made the discovery, have determined it to be nearly 90 percent pure. They also say the only way for the substance to be present there is if there was an abundance of water present on the planet sometime in its past. The water would have been superheated and coming up through hydrothermal vents or even hot springs which scientists say would have been similar to ones already present at Yellowstone National Park in Wyoming.

Hydrothermal vents are fissures with superheated water and gases venting from the planet's surface. The vents are usually found around highly volcanic areas at the bottoms of seas and oceans. To this day, these vents or evidence of them have only been found on Earth. "On Earth, the only way to have this kind of silica enrichment is by hot water reacting with rocks. Home Plate came from an explosive volcanic event with water or ice being involved. We saw where rocks were thrown into the air and landed to make small indentations in the soft, wet ash sediment around the vent," said Dr. Steven Ruff of Arizona State University (ASU) in Arizona, one of the authors of the announcement of the findings published in Science.

The finding has lead to more questions about Mars and whether or not it once had life present on it, and if so, where and how much.

"On Earth, hydrothermal deposits teem with life and the associated silica deposits typically contain fossil remains of microbes. What we can say is that this was once a habitable environment where liquid water and the energy needed for life were present," said another author of the report, Dr. Jack Farmer also from ASU.

Ruff also states that much of the area Mars already searched seems to be covered with silica. "It's not just the soil in a trench in one place. It's a broader story of outcrops that extend 50 meters [about 150 feet] away from Home Plate. It's not a small scale, modest phenomenon."

Spirit is the first of two rovers which landed on Mars in January of 2004. The second rover is Opportunity and both are still operating nearly 20 times longer than NASA has expected.