Below are examples of some of the questions that drive our scientific research!
We study the interiors of the solid planets and moons in the Solar System, and how they change over time and what they tell us about a world's evolution. We analyzing data from spacecraft missions, including gravity and topography data, and numerically model relevant processes with computer simulations, including heat transport and interior convection. Examples of our work in this area include showing how topography is supported on the Moon, constraining crustal thickness on Mercury, and showing that Ceres may be an icy, frozen ocean world
LOLA and GRAIL datasets showing the topography (left) and gravity (right) of the Moon, respectively. Topography and gravity are two of the most important types of data we use to study planetary interiors.
What are the interior structures of the planets and moons of our Solar System, and how have they evolved over time?
Bright deposits in Occator crater (left) and the mountain Ahuns Mons (right), on Ceres. We have studied these features, both of which have been proposed to cryovolcanic, using a variety of datasets and techniques. Data and images come from NASA's Dawn mission.
We study how planetary interior processes manifest at the surface, and how planetary surfaces are controlled or affected by planetary interiors. Volcanism on rocky worlds and cryovolcanism on icy worlds reflect the thermal history of their worlds and in some cases are closely tied to their worlds' orbital history or climate history. Other interior processes, like internal convection, can also control what we observe at the surface of a planet. Examples of our work on these topics include estimating cryovolcanic eruption rates on Ceres, quantifying the basaltic volcanic history of the Moon, inferring the thermal history of a world from observing and modeling relaxed craters at its surface, and testing the connection between cryovolcanism and surface features on Pluto's moon Charon.
What are the connections between planetary interiors and surfaces, and what do surface features tell us about a world's evolution and interior processes?
Ices on planetary surfaces may form thick deposits over many years, recording information about the climate history of their world. Ices and volatiles may also migrate over time in response to changing conditions, and understanding how they move around planetary surfaces can help us discover their origin or understand how they shape landscapes. We develop techniques for analysis of observed ice deposits and use volatile transport models to understand how ices migrate over time. Examples of our work on these topics include showing how polar ice deposits on Mars record the planet's recent climate history and showing how canyons and craters on the moons of Uranus may be traps for carbon dioxide ice.
HiRISE image showing icy stratigraphy on Mars (left). Voyager 2 image of Uranus' moon Umbriel (right), showing bright feature at top we propose is carbon dioxide ice using our volatile transport models.
What do ices on planetary surfaces tell us about the history of climate or volatile transport on that world?
How can we address the questions above with spacecraft missions?
We want to address the above research questions not only by analyzing and interpreting current data – but also drive the field forward by thinking about these questions could be addressed through new spacecraft missions and measurements. We quantify how our ideas could be tested with future spacecraft observations and study the best paths forward for the geophysical exploration of the Solar System. Examples of our work on these topics include developing the science case for geodetic observations beyond the Earth-Moon system and studying the best paths forward for relatively low cost exploration of Mars.
Artist depiction of the two GRAIL spacecraft in lunar orbit.