Radar images by NASA’s Mars Reconnaissance Orbiter show that the polar ice caps of Mars are coming out of an ice age that began about 370,000 years ago, according to a new study.
The analysis of data collected by NASA’s Mars Reconnaissance Orbiter shows that about 87,000 cubic kilometers of ice have accumulated at the poles since the end of the last ice age.
Researchers have found an increase in ice at Mars’ north pole is consistent with the long-term drop in temperature associated with an ice age.
“We found an accelerated accumulation rate of ice in the uppermost 100 to 300 metres of the polar cap,” said the Isaac Smith, lead author of a paper published the journal Science, in a statement. “The volume and thickness of ice matches model predictions from the early 2000s.”
Unlike on Earth, the polar ice caps on Mars grow during warmer periods. This is because of the tilt of Mars’s axis can shift by as much as 60 degrees, exposing different parts of the planet to the heat of the sun.
When Mars is tilted 60 degrees, its North Pole faces the sun which starts an ice age. As warming at the poles melts polar ice to water vapor, it gets absorbed by the planet’s thin atmosphere, and then be transferred to the cooler mid-latitudes where it condenses into snow or frost.
The study is the first to map the ice deposits on the north and south pole. Scientists can now use the new ice measurements to create more accurate models of the Martian climate.
“Previously those models were unconstrained by observations so they started with guesses. Now they have more to run on,” Smith said.