Kellie Wall, an undergraduate student from Washington State University, recently discovered a new way to detect water on Mars and other planets by looking at how crystals form inside volcanic rock.
Wall, along with her fellow researchers, learned how to measure the crystal formations of a rock's groundmass, or that part of the rock made of finer materials where crystals are often embedded.
Volcanic rock, or basalt, on Earth often starts out as a liquid, but cools quickly when subjected to water. This process makes the rock solid almost instantaneously, creating something that is similar to glass. Volcanic rock not exposed to water cools slower, which forms crystal in the groundmass. This suggests that volcanic rock exposed to water has less crystal formations than rock that is not exposed to it.
Wall first tested this on rocks found on Earth.
"The rocks that erupted and interacted with water, which we call phreatomagmatic, all had a groundmass crystallinity as low as 8 percent and ranging up to about 35 percent," says Wall. "The rocks that erupted without interaction with water had groundmass crystallinities from about 45 percent upwards to almost totally crystalline."
Wall also had access to volcanic soil samples from Mars. In her follow-up tests, she found that those rocks were not exposed to water in their creation.
This suggests that a new way of detecting water on Mars, as well as other planets, could be as simple as studying rock formations.
Water is a key component for sustaining life, so the existence of it on planets other than Earth, suggests that there is life out there, at least in microbial form. Learning how to detect water easier could aid scientists in future missions to the Red Planet and beyond.
"I think this quantification of volcanic textures is a new facet of the water story that hasn't yet been explored," says Wall. "Most of the studies searching for water have focused on either looking for sedimentary structures -- large- and small-scale -- for evidence of water, or looking for rocks like limestones that actually would have formed in a water-rich environment."
Although volcanoes fascinated Wall as a child, she began her college experience as a communications major. However, after taking a geology class for a science credit, she loved the subject so much that she changed her major. By her sophomore year, her professors asked her to study volcanic activity on both Earth and Mars, which led to this discovery.
