Mars' ancient lakes may have used thin ice lids to stay liquid

Researchers used Curiosity data and a Mars-adapted climate model to run 64 simulations of a Gale crater lake and found that thin, seasonally disappearing ice lids could thermally insulate liquid water for decades under cold early-Mars conditions.

New research suggests thin ice layers could have insulated lakes on ancient Mars and kept surface water liquid as the planet cooled. The study used rock and mineral data collected by NASA's Curiosity rover in Gale crater and adapted an Earth climate tool for Mars. The team created the LakeM2ARS model and ran multiple simulations representing conditions about 3.6 billion years ago. Some simulations produced thin seasonal ice lids that melted in spring and summer and reformed in winter, preserving liquid water below. Key findings: - The researchers adapted Proxy System Modeling into a Mars-specific tool called LakeM2ARS using Curiosity's rock and mineral proxies. - They ran 64 simulations of a hypothetical lake in Gale crater, each spanning 30 Martian years (about 56 Earth years). - Many simulations formed thin winter ice lids that thermally insulated liquid water beneath and melted seasonally with little net loss of liquid volume. - Some model runs froze solid in winter, indicating varied outcomes depending on specific conditions. - The authors report that these results offer a physical mechanism to explain persistent surface water on a generally cold early Mars and do not rule out warmer periods in Mars' history. Summary: The results provide a physical mechanism that could help reconcile geological evidence of past surface water with a generally cold early Mars. If similar patterns occurred elsewhere on the planet, the authors say thin, seasonally changing ice lids could have supported year-round liquid water in some lakes. Undetermined at this time.