Sentences with phrase «active hydrologic»

But a large piece of the puzzle is missing, he added, because climate models have not been able to reproduce an early Mars climate sufficiently warm enough to promote an active hydrologic cycle.

The study bolsters the idea that Mars once had a warmer climate and active hydrologic cycle, with water evaporating from an ancient ocean, returning to the surface as rainfall and eroding the planet's extensive network of valleys.