Volcanism in the distant past of the planet Mars is the possible cause of the formation of the important ice deposits that are buried in the equatorial zone of the planet, according to a new study published on October 14 in the journal Nature Communications.
Previous research has concluded that Mars is rich in ice, but most of these deposits are located at the poles of the planet, as is the case with Earth. However, recently the Mars Odyssey probe and the ExoMars Trace Gas Orbiter spacecraft have detected high levels of hydrogen near the ground in the equatorial regions of Mars. This ice could have survived for long periods of time if it had been buried under dust or volcanic debris and could still exist beneath the surface of the Red Planet’s equatorial regions, reports
If the measurements and their interpretation are accurate, the researchers wonder how these ice deposits could have been maintained in a region so exposed to solar radiation. Previous studies noted that a possible origin of this frozen water could be volcanism, which released large amounts of water vapor.
Using computer models of the Martian climate, the researchers simulated volcanic eruptions identified by the conclusions of previous research, which occurred on Mars 4.1 billion to 3 billion years ago. These simulations suggested that the eruptions released water vapor at high altitudes, which could have frozen in the cold Martian atmosphere and then fallen to the ground as ice. They found that a single three-day eruption could have led to the formation of ice deposits up to 5 meters thick in the area around a volcano.
“Imagine how much ice could be produced after repeated eruptions over millions of years,” lead study author Saira Hamid, a planetary scientist at Arizona State University, Tempe, told Space.com.
“Explosive volcanism could repeatedly seed the low latitudes with ice and ash, producing buried or isolated ice deposits that help explain the excess hydrogen signals measured near the equator,” she argued.
However, Hamid cautioned that the hydrogen detected by spacecraft around the Martian equator may not come from ice deposits, but from a number of mineral deposits, among other possibilities. Future research can look for signs of ash-covered ice in the equatorial regions of Mars to support or disprove the existence of ice there, she added.
If these equatorial pockets of ice exist on Mars, they could prove valuable to human explorers there.
“Our study suggests that volcanic regions could be priority targets,” Hamid noted.
Additionally, volcanic eruptions could have released sulfuric acid into the Martian atmosphere. This could have generated aerosols that reflected sunlight and cooled the Red Planet, throwing it into a global winter, which in turn could have allowed ice to accumulate for a long time.
But the same ancient Martian volcanic eruptions could also have generated heat and chemicals that could have created short-lived habitable environments, Hamid said.
“These regions could have provided transient but potentially life-friendly conditions. Understanding where and how these ice and ash deposits formed could help guide the search for past or even preserved biosignatures on Mars,” she added.
