Like the Earth, Mars goes through cycles in its climate driven by periodicities in its orbit (i.e, the Martian Milankovitch cycles). The layering seen in the polar deposits of Mars likely records these variations in climate, but deciphering this history has proved elusive, until now. Becerra et al.  used spectral analyses to correlate periodicities in the layering of the South Polar Layered Deposits (SPLD) to orbital oscillations that drive climate change.
Their results permit determination of the accumulation rates in the SPLD, unravelling the recent climate history of Mars and constraining how dust is moved around the planet. Assuming no major hiatuses or periods of erosion, it appears the SPLD formed over 10 to 30 million years. In addition, the time range recorded in these layers is longer than the time range over which models of Mars’s orbit are valid. Consequently, this work may extend our knowledge of the orbital variations of the planet beyond approximately 20 million years, where the orbital models break down, allowing a deeper look into the past of the climate of the Red Planet.
Citation: Becerra, P., Sori, M. M., Thomas, N., Pommerol, A., Simioni, E., Sutton, S. S., et al . Timescales of the climate record in the south polar ice cap of Mars. Geophysical Research Letters, 46. https://doi.org/10.1029/2019GL083588
—Andrew Dombard, Editor, Geophysical Research Letters