- Briny, liquid water may form in the shadows of large boulders during Martian winters.
- Scientists created computer simulations to better understand the conditions in which this salty water ice melts.
- Over the course of a day, they found that the water ice could warm from -262 degrees Fahrenheit to -50 degrees Fahrenheit.
Boulders strewn across the surface of mid-latitude Mars may be the key to finding liquid water on the red planet. Scientists calculated that water ice could have the ability to form in the shadows of some of the boulders during the winter months.
In the springtime, when the sun rises again, everything changes.
A team of researchers ran a set of computer simulations and found the sun’s rays would heat water ice tucked in the large rocks' shadows from -262 degrees Fahrenheit to -50 degrees Fahrenheit—sometimes just over the course of a quarter of a day—leaving small pools of briny water.
“Mars has plenty of cold ice-rich regions and plenty of warm ice-free regions, but icy regions where the temperature rises above the melting point are a sweet spot that is nearly impossible to find,” astrophysicist Norbert Schorghofer of the Planetary Science Institute in Tucson, Arizona, said in a statement. “That sweet spot is where liquid water would form,” The scientists published their research in the Astrophysical Journal yesterday.
Salt lowers the melting temperature of ice, so under these conditions, water ice sitting atop the briny soils immediately begins to melt first before sublimating away into the atmosphere. During the rest of the year, water ice that forms quickly sublimates into the atmosphere, leaving no liquid behind.
Water ice isn’t the only thing trapped in the shadows of these large rocks. During the frigid winter, Schorghofer's models have found that a frosty layer of carbon dioxide ice builds up, too. But this ice is the first to disappear once spring rolls around. The day it fully melts is called the “Crocus date,” and any melting that happens afterward is referred to as “crocus melting.”
Unraveling how and when these different types of ice melt from Mars’s surface wasn’t easy. “It took decades to develop the necessary quantitative models,” Schorghofer said.
You Might Also Like