Mars

Planetary geology provides critical information of other worlds, including their astrobiological potential.  By that term, I mean not only their specific potential to harbor life but their more general potential to tell us something about life.  As we expand our understanding of life – where it is, what it is, how it is – beyond Earth, geomorphology complements compositional data in giving us clues as to planet habitability.  Mars is a case in point: the earliest to most recent data show extensive geomorphic evidence of water, the sine qua non for all life that we know.  These remote and (r

Water ice clouds are an important part of the martian hydrological cycle, influencing the water and energy budgets. Microphysical models can be used to study the connections between cloud formation and water distribution throughout the system (for example, as surface frost layers), but only if the intricacies of cloud formation and growth are understood and properly parameterized. To that end, we have performed laboratory studies of water ice nucleation on a variety of surrogate materials and have found that initiation of ice is more difficult than often presumed.

The paradigm for the general circulation of the Mars atmosphere is of a slow, overturning Hadley Cell with a seasonally-shifting rising branch that follows peak insolation. The Hadley cell is often cited as the dominant circulation responsible for the transport of dust, water, energy, and mass, although it has never been directly observed. Recent observations, over a decade of numerical modeling studies, and a glimpse back at Earth's circulation suggest that the simplistic notion of a Mars Hadley Cell is insufficient to describe the actual circulations responsible for transport.