We are interested in using a variety of approaches to characterize Mercury, one of the terrestrial planets, in order to further our understanding of the formation and evolution of planets like Earth.

Earth-based Observations

We measured the spin state of Mercury with radar speckle tracking to probe the interior of the planet. In 2007, we found that Mercury has a molten core. Links and illustrations related to our Science paper can be found here.

We used Earth-based observations over a period of 10 years to characterize the spin state of Mercury in great detail, which enabled a measurement of the moment of inertia of Mercury and the size of its core. A 2012 JGR paper summarizes our findings.

Science Magazine Cover Illustration

MESSENGER Observations

We combined gravity information from MESSENGER with our spin state measurements to characterize the interior of Mercury.

We also modeled the response of a planet to the influence of solar tides, and we found that one can place additional constraints on the nature of the interior by measuring the tidal amplitude.