The red planet is known for being a dusty wasteland, but scientists have found evidence that it experienced an ice age 400,000 years ago - and is still recovering from it.
Like Earth, ice ages on other planets are driven by "long-term cyclical changes in the planet’s orbit and tilt”, meaning solar radiation differs between poles.
Mars, much like Earth, experiences seasonal changes, though they are much more noticeable on the planet because its tilt changes much more than that of Earth.
A team from the Southwest Research Institute used radar data collected from a Nasa reconnaissance mission on Mars.
Using the radar data, the team found an "accelerated accumulation rate of ice” in the uppermost portion of the planet’s polar cap – suggesting that the ice age occurred.
"The volume and thickness of ice matches model predictions,” said Isaac Smith, a researcher at the institute and lead author of the study, which has been published in Science.
"Radar observations of the ice cap provide a detailed history of ice accumulation and erosion associated with climate change.”
As the planet tilts, its climate also changes.
"Because the climate on Mars fluctuates with larger swings in tilt, and ice will distribute differently for each swing, Mars would look substantially different in the past than it does now,” said Smith.
Data shows that around 87,000 cubic kilometres of ice have built up on the planet since the last ice age, which the team says is "a means to understand the accumulation history”, and support computer modelling of the martian climate.
The data, whilst telling us more about the climatic conditions of Mars, could also represent what the team call "a simplified laboratory for understanding climate science on Earth”.
It will also help us better understand how to adapt to a martian climate.
"Studying ice on Mars also is important to the future of human exploration of the Red Planet," said Smith. "Water will be a critical resource for a martian outpost.”
This article was originally published by WIRED UK
