Ari Koeppel, a Ph.D. candidate at Northern Arizona University (NAU), and Johns Hopkins University (JHU) have revealed that Arabia Terra, a region on Mars, once had water.
Arabia Terra is a huge highland terrain in Mars' northwestern hemisphere, largely in the Arabia quadrangle but with a tiny portion in the Mare Acidalium quadrangle. It is cratered and eroded to the point of near-total destruction. Arabia Terra is said to be one of the planet's oldest terrains based on its shattered topography.
The focus of Koeppel's research, along with his advisor, associate professor Christopher Edwards of NAU's Department of Astronomy and Planetary Science, Andrew Annex, Kevin Lewis, and undergraduate student Gabriel Carrillo of Johns Hopkins University, was on these rock layers and how they formed.
Their study titled "A fragile record of transient water on Mars" was supported by the NASA Mars Data Analysis Program and published in the journal Geology.
Koeppel said that "we were especially interested in studying rocks on Mars' surface to acquire a better understanding of former settings three to four billion years ago, and if there may have been climatic conditions that were conducive for life."
"For us, it was essential to know whether there was stable water, how long it may have been stable, what the atmosphere was like, and what the surface temperatures were like."
Thermal inertia, which describes a material's capacity to alter temperature, firmly focused on the scientists' investigation into how the rock layers formed. When it comes to heat, sand loses it rapidly, whereas boulders retain it for lengthy periods. They were able to identify the physical qualities of rocks in their research region by observing the surface temperatures. While the material seemed solid, they could determine when it had begun to disintegrate.
According to Edwards, "no one has done an in-depth thermal inertia examination" of the "very intriguing deposits" that blanket most of Mars' surface.
Koeppel completed his research using satellite remote sensing devices. Geologists on Earth use rocks to communicate tales about former ecosystems, Koeppel said. "We're a little more constrained on Mars. Our research relies heavily on satellite data, so we can't merely walk to a rock outcrop and take samples from it. One of the few satellites circling Mars is equipped with several types of equipment used to study the planet. To characterize the rocks that are on the surface, each instrument has a specific job to perform."
Thermal inertia, erosion evidence, the state of the craters, and the minerals present were all examined using the data collected remotely.
"We discovered that these deposits are significantly less cohesive than previously anticipated, indicating that this environment could only have had water for a short period," Koeppel said.
"For some, it deflates the tale since we tend to assume that more water for a longer period indicates a larger likelihood that life formerly existed there. But it's fascinating to us because it raises a whole new set of issues. What are the circumstances under which water may have been present for a limited period? Is it possible that glaciers may have melted swiftly in the face of massive floods? For how long might water has percolated up out of the Earth before sinking back to the depths?"
"I desired to learn more about other planets that first drew me to the field of planetary research. Even Mars is just the tip of the iceberg when it comes to the size of the cosmos, "According to Koeppel.
"However, we've been studying Mars for many decades and have a substantial amount of data to draw upon. It's an exciting moment for Mars research because we're now studying it at a level that's on par with how we've studied Earth."
Ari H.D. Koeppel, Christopher S. Edwards, Andrew M. Annex, Kevin W. Lewis, Gabriel J. Carrillo; A fragile record of fleeting water on Mars. Geology 2021; DOI: https://doi.org/10.1130/G49285.1