PLANETARY MUSINGS

Predicted recovery of Mercury's internal structure by MESSENGER

A major focus of research in our group over the last several years and now looking forward with our involvement with the MESSENGER is the planet Mercury. A question of primary interest to the scientific community is the origin of the planet's large bulk density and the nature of its core. Recent work by Jean Luc Margot of Cornell and colleagues recently demonstrated that Mercury likely has a core that is at least partially molten. This is an important advance, and the MESSENGER mission will bring more, particularly through measurement of the planet's low-degree gravity field.

In preparation for MESSENGER's arrival we have calculated a series of models of Mercury's internal structure in order to estimate how well new data will constrain the state of the interior. Working with Sean Solomon (CIW) and Derek Smith (former Case student now pursuing a Ph.D. at Dartmouth) we have calculated that within current estimates of the quality of MESSENGER's forthcoming measurements that it may be possible to determine the size and density of Mercury's core and mantle with considerable confidence, especially for a body for which we have no samples and placed no landers nor seismometers on its surface.

The results of this work were recently published in Geophysical Research Letters.

Hauck, Steven A., II, Sean C. Solomon and Derek A. Smith, Predicted recovery of Mercury's internal structure by MESSENGER, Geophys. Res. Lett., 34, L18201, doi: 10.1029/2007GL030793 (2007). Article