Water is abundant both on Earth and in our own solar system. Water ice has been detected on the moon, comets and Saturn’s rings, among other places in the solar system. Studies have determined that water played an important role in the initial formation of our solar system. To learn more about the role of water, the researchers looked for evidence of liquid water in meteorites.
The researchers found water such as hydroxyls and molecules in meteorites in the context of water minerals. A hydrated mineral is essentially a solid with a little ionic or molecular water incorporated into it. Scientists have now discovered inclusions of liquid water within salt crystals located within a class of meteorites known as chondrites.
Chondrites represent the vast majority of all meteorites found on Earth. The researchers found that the salt inside this type of meteorite originated from other, more primitive parent objects. The team wanted to determine whether the water inclusions present in meteorites are a form of calcium carbonate known as calcite within a class of meteorites known as carbonaceous chondrites.
The team examined samples from the Sutter’s Mill meteorite, which is a carbonaceous chondrite that originated from an asteroid that formed 4.6 billion years ago. Using advanced microscopy techniques, the team found a calcite crystal containing an inclusion of nanoscale aqueous fluid with at least 15 percent carbon dioxide. The finding confirms that calcite crystals in ancient carbonaceous chondrites may contain not only liquid water, but also carbon dioxide.
The researchers say that the presence of inclusions of liquid water in the meteorite has implications for the origins of the asteroid parent of the meteorite and the early history of the solar system. They believe that the inclusions probably occurred due to the formation of the parent asteroid with pieces of frozen water and carbon dioxide inside it. This means that the asteroid would have formed in a part of the solar system that was cold enough for water and carbon dioxide to freeze, probably out of Earth’s orbit and possibly beyond Jupiter’s orbit.