A new study has shed light on the potential water-rich history of the red planet.
According to new research conducted by the Department of Energy’s Lawrence Berkeley National Laboratory and the University of Nevada, Las Vegas, a mineral found in Martian meteorites may have originally contained hydrogen indicating Mars could have contained a wetter environment than previously thought.
“This is important for deducing how much water could have been on Mars, and whether the water was from Mars itself rather than comets or meteorites,” Martin Kunz, a staff scientist at Berkeley Lab's Advanced Light Source who participated in X-ray studies of the shocked whitlockite samples, said in a statement.
The researchers simulated the Martian meteorites and created a synthetic version of whitlockite—a hydrogen-containing mineral.
They conducted after shock-compression experiments on whitlockite samples to simulate the conditions of ejecting meteorites from Mars and studied their microscopic makeup with X-ray experiments.
This showed that whitlockite can become dehydrated from such shocks, forming merrillite—a mineral that is commonly found in Martian meteorites but does not occur naturally on Earth.
“If even a part of merrillite had been whitlockite before, it changes the water budget of Mars dramatically,” Oliver Tschauner, a professor of research in the Department of Geoscience at UNLV who co-led the study with Christopher Adcock, an assistant research professor at UNLV, said in a statement.
Tschauner explained that because whitlockite can be dissolved in water and contains phosphorous, the research could indicate that life is possible on Mars.
“The overarching question here is about water on Mars and its early history on Mars: Had there ever been an environment that enabled a generation of life on Mars?” Tschauner said.
The pressure and temperatures generated in the shock experiments are comparable to those of a meteorite impact but lasted for only about 100 billionths of a second—about one-tenth to one-hundredth as long as an actual meteorite impact.
However, because the experiments showed even partial conversion to merrillite in the lab-created conditions, a longer duration impact would likely have produced almost full conversion to merrillite, according to Tschauner.
The researchers blasted the synthetic whitlockite samples with metal plates fired from a gas-pressurized gun at speeds of up to about half a mile per second or about 1,678 miles per hour and at pressures of up to about 363,000 times greater than the air pressure in a basketball.
At Berkeley the researchers used an X-ray beam to study the microscopic structure of shocked whitlockite samples in a technique called X-ray diffraction.
Separate X-ray experiments showed that 36 percent of whitlockite was transformed to merrillite at the site of the metal plate’s impact with the mineral and that shock-generated heating rather than compression may be the most important factor in whitlockite’s transformation into merrillite.
Adcock and Tschauner are now trying to use infrared light at ALS to study actual Martian meteorite samples and are also planning X-ray studies of these actual samples.
The study was published in Nature Communications.