More Water in the Early Solar System?

The mineral whitlockite synthesized in the Hausrath Research Lab.
Mar. 6, 2017

Geoscientist Christopher Adcock and a team of international researchers recently published a research article titled, “Shock-transformation of whitlockite to merrillite and the implications for meteoritic phosphate” in Nature Communications.

The research focuses on how shock can dehydrate minerals in meteorites, specifically, a phosphate mineral that commonly occurs in meteorites, including Martian meteorites.

The amount of water in meteorites is often used to understand water contents in the early solar system and on planets such as Mars. This water content has important implications for the origins of our solar system and the possibility of life outside of Earth. All meteorites have experienced shock and the research team shows that shock may dehydrate phosphate minerals within meteorites. This means Mars and the early solar system may have had more water than previously thought.

Merrillite, which contains no water, is a mineral commonly found in Martian meteorites but one that does not occur naturally on Earth. The researchers created a synthetic of merrillite by shocking a hydrated form of the mineral, called whitlockite, in a simulated impact of a meteor striking Mars.

The team performed high pressure shock experiments on these minerals at UNLV by loading the mineral in a capsule that is shot into a target by a helium gun, fired at over 1,500 miles per hour. The minerals were analyzed before and after at multiple synchrotrons in the United States, including Berkeley Lab’s Advanced Light Source and at Argonne National Laboratory’s Advanced Photon Source. They showed significant devolatilization of the minerals from shock levels common for meteorites.

“Although meteorites have been of immense value as samples of our solar system and other planetary bodies, they have all experienced and been altered by shock,” Adcock said. “We need sample return missions.  Some of our biggest questions, like about life, may only be answered by unshocked samples directly returned from places such as Mars.”

The multinational team was led by a UNLV group from the Department of Geoscience and the High Pressure Science and Engineering Center at UNLV.