Study Indicates Mars Had Cold Icy Conditions
The question of whether Mars ever supported life has fascinated scientists and the public for decades. Central to this inquiry is understanding the planet’s past climate: was it warm and wet, akin to Earth’s climate, or was it cold and icy, making it less likely to support life as we know it? A recent study points to the latter, drawing parallels between Martian soils and those found in the subarctic climate of Newfoundland, Canada.
Published on July 7th in Communications Earth and Environment, the study sought to find Earth soils similar to those in Mars’ Gale Crater. Soils are key to understanding environmental history, as their mineral composition can reveal landscape evolution over time. By studying these materials, scientists hope to answer long-standing questions about Mars’ historical conditions. The Gale Crater soils record Mars’ climate from 3 to 4 billion years ago, a period when water was more abundant on the planet, coinciding with the emergence of life on Earth.
“Gale Crater is a paleo lakebed-there was obviously water present. But what were the environmental conditions when the water was there?” says Anthony Feldman, a soil scientist and geomorphologist now at DRI. “We’re never going to find a direct analog to the Martian surface, because conditions are so different between Mars and Earth. But we can look at trends under terrestrial conditions and use those to try to extrapolate to Martian questions.”
The formation and preservation of amorphous materials on Mars provide crucial insights into the planet’s past climate. NASA’s Curiosity Rover discovered significant amounts of these materials in the soils of Gale Crater, indicating they were likely formed in the presence of water. However, their lack of crystalline structure suggests that specific conditions were necessary to prevent them from transforming into more stable mineral forms over time.
Feldman and his team found that the subarctic conditions in Newfoundland, Canada, were conducive to the formation and preservation of amorphous materials. The cold, near-freezing temperatures and presence of water in these regions seem to be key factors in slowing down the crystallization process. This suggests that the abundance of amorphous materials in Gale Crater could be indicative of similar subarctic conditions on Mars billions of years ago.
Typically, amorphous materials are considered unstable because their atoms have not yet organized into a crystalline structure. However, under certain kinetic conditions, such as extremely low temperatures, the rate of crystallization can be significantly slowed down, allowing these materials to persist over geologic timescales. “There’s something going on in the kinetics-or the rate of reaction-that is slowing it down so that these materials can be preserved over geologic time scales,” Feldman explains.
The researchers suggest that the cold, near-freezing conditions observed in subarctic regions like Newfoundland could be one of the kinetic limiting factors that enabled the formation and preservation of amorphous materials on Mars. “What we’re suggesting is that very cold, close to freezing conditions, is one particular kinetic limiting factor that allows for these materials to form and be preserved,” Feldman states.
