SALT LAKE CITY (AP) -- University of Utah researchers say rocks uncovered on Mars are very similar to those in the southern part of the state, and could help scientists determine whether life existed on the Red Planet.
The rocks, discovered by the Opportunity rover, are known as "concretions," but have been nicknamed "blueberries" because of their typical size and shape. They're essentially a kind of cement, and are formed on Earth when water or other liquids flow through porous rock.
The researchers published their work comparing the two rocks in the June 17 issue of scientific journal "Nature." The research suggests the Utah rocks are a good terrestrial substitute for Mars, and that groundwater flow had to exist to form the rocks -- a key part of the puzzle for researchers because the presence of water is considered essential for life.
If they are similar, it would mean NASA researchers could study the Utah rocks firsthand. They won't be able to bring the Mars rocks back for several years.
The rocks are often multicolored on the inside and gray on the outside. They're sometimes referred to as "Moqui Marbles," and believed by some to have mystical powers.
Marjorie Chan, the university's geology chair and a lead scientist in the study, said research on the concretions is relatively new. She's been studying them for eight years.
"Geologically, they've been there for millions of years," she said. "They've always been considered a geologic oddity in how they formed."
Others, including NASA, began to take much more interest in Chan's research after the concretions were discovered on Mars.
"Once the Opportunity rover landed, I think we knew more about what was going on as an analog," she said. "When the team got there, they weren't thinking that those things might be there."
Though concretions exist in many parts of the world, Chan said they're particularly useful in Utah because they're more accessible in some of the state's "red rock" area. That landscape is painted red by hematite, just like some of the land on Mars.
Scott McLennan, a NASA mission scientist for the Mars exploration rovers, said the Utah research would be helpful, but that atmospheric differences on Mars and Earth could mean the rocks aren't that similar.
"It's always useful to try to find Earth-based analogs for everything that is happening on Mars," he said. "But the conditions on Earth and Mars are likely to be very different. There are some similarities, but I suspect also significant differences."
Still, McLennan said researchers would be comparing the Mars rocks to those found in Utah and elsewhere.
"There's no doubt that this kind of study is important -- whether they're the same or different," he said.
The Mars findings ultimately changed the focus of Chan's research.
"We're looking into that component about life on Mars," she said. "We know that hematite is one of the few minerals that really is strongly related to water.
"It's intensifying the search for life."
(Copyright 2004 by The Associated Press. All Rights Reserved.)