Scientists have stumbled upon a cache of ice that is believed to be the remnants of ancient polar ice sheets of Mars.
The discovery could provide clues about the history of the Red Planet, including whether it once had conditions capable of supporting life.
Scientists Find Ancient Martian Polar Ice Sheets
The team from the University of Texas and the University of Arizona made the discovery using data from the Mars Reconnaissance Orbiter's Shallow Radar, or SHARAD. The instrument emits radar waves that can penetrate up to a mile and half beneath the surface of the planet.
They claimed that the layers of ice, which are buried a mile beneath the north pole of Mars, could be one of the largest reservoirs of water on the planet. If melted, the reservoir would cover the entire surface of the planet with water.
"We didn't expect to find this much water ice here," stated Stefano Nerozzi, a graduate research assistant at the University of Texas and one of the authors of the study. "That likely makes it the third largest water reservoir on Mars after the polar ice caps."
Scientists previously assumed that the ancient polar ice caps of Mars have long disappeared. However, the study provides evidence that a large number of ice sheets survived underneath the surface of the Red Planet. The ice sheet remnants, according to the researchers, sandwiched under alternating layers of sand.
Buried Ice And Sand Caps Provide A Look At Ancient Mars
The authors of the study said that the layers of ice and sand could unlock secrets about the conditions in ancient Mars. Like tree rings, the layers of ice and sand provide a record of glacial events. The Red Planet has experienced several ice ages throughout its lifetime due to the variations of its orbit and tilt.
Studying Mars' history of polar glaciation can help give a definitive answer on whether Earth's neighboring planet was ever habitable.
"Understanding how much water was available globally versus what's trapped in the poles is important if you're going to have liquid water on Mars," added Nerozzi. "You can have all the right conditions for life, but if most of the water is locked up at the poles, then it becomes difficult to have sufficient amounts of liquid water near the equator."
The discovery was published in the journal Geophysical Research Letters on Wednesday, May 22.