Water may have lasted longer on Mars than previously thought.
According to a new study, published in the journal Icarus, liquid may have been present on Mars as recently as 200,000 years ago. The findings come after researchers studied a particular crater on the Red Planet that has well-preserved gullies and debris flow deposits that seem to have been created with water.
"Our fieldwork on Svalbard confirmed our interpretation of the Martian deposits. What surprised us was that the crater in which these debris flows have formed is so young," Andreas Johnsson from the University of Gothenburg in Sweden and author of the study said in a statement.
Johnsson and his colleagues came to their conclusion after comparing debris flows on a Svalbard, a Norwegian archipelago in the Arctic Ocean, with those on a crater located on Mars’ southern hemisphere. Debris flows, also known as mudslides, are when a mixture of sediment and water give way to gravity on a slope that can travel with tremendous force.
The new study concludes that the Mars crater is approximately 200,000 years old, suggesting it was formed after the recent ice age on Mars that ended around 400,000 years ago. While gullies are commonly found on Mars, the previously studied ones are older and associated with the ice age.
"Our study crater on Mars is far too young to have been influenced by the conditions that were prevalent then,” Johnsson said, referring to the past ice age on Mars. “This suggests that the meltwater-related processes that formed these deposits have been exceptionally effective also in more recent times."
Exactly how the water formed on Mars remains a mystery. According to Johnsson, this particular crater may have held liquid from melting snow, rather than from an ice-rich ground.
"My first thought was that the water that formed these debris flows had come from preserved ice within the rampart ejecta. But when we looked more closely, we didn't find any structures such as faults or fractures in the crater that could have acted as conduits for the meltwater,” Johnsson said. "It is more likely that the water has come from melting snow packs, when the conditions were favorable for snow formation. This is possible, since the orbital axis of Mars was more tilted in the past than it is today.”