The study, published in Science, confirms what models had predicted years ago, but weren't previously able to prove: that Mars has had several ice age cycles in the past. Using the Mars Reconnaissance Orbiter, a NASA spacecraft filled with instruments for surveying the red planet, researchers analyzed radar images of its polar ice caps. Tracking erosion and wind effects told a story of how the ice advanced and receded over time -- and gave the researchers a timeline for when the last ice age ended.
Studying Mars' climate change gives us a parallel to the global warming occurring on Earth. The former is the closest planet in the solar system to our own, making it a decent laboratory to study how a similar atmosphere would look without a over a century of burned fossil fuels. But if we're going to send humans to Mars one day it's a good idea to figure out its weather and water situation.