Tides, Orbit, and Gravity of the Moon



I am intersted in novel tidal and orbital dynamics processes applied to the early Moon (PDF).  Such processes can tell us about the orientation, gravity field, orbital state, and possibly the global geology and geochemisty of the Moon we see today.  I am also interested in how accretional processes in the debris disk after the giant impact may have affected the evolution of the Moon.

Above: one component of the lunar tidal potential.

Lunar Paleomagnetism

 

Planetary magnetism is an excellent means of understanding the thermal history and internal workings of a body.  By studying the magnetic remanence in lunar samples brought back by the Apollo missions we hope to determine if the Moon's interior ever developed a magnetic dynamo.  Much of the work on lunar magnetism stopped by the mid 1980s, but there are good reasons to continue its study.  In particular, the remanence in very old samples has not been fully explored.  Also, instrument sensitivty and measurement techniques are now much better, and much less sample material is required to obtain useful results.

Above (left to right): Source boulder for 78235/6, 78236 in the lab on a 3 mm diameter quartz rod, a mosaic I pieced together showing the small source crater for 78155, and 78155 in the lab on a 2.5 cm diameter quartz disc. 

Lunar Basins: Geology, Geochemistry, and Geophysics





Thorium is a great tracer element for understanding the thermal and chemical evolution of the lunar crust.  It is also easily measured from orbit.  I am interested in what thorium in the farside South Pole-Aitken basin tells us about global lunar evolution (PDF).  I am also intersted in what controls the appearance of structural features of the largest basins in general.  What can the largest basins tell us about large-scale properties of the bodies they impact?

Above: topography, thorium, and a multispectral image of the lunar South Pole-Aitken basin.

Engineering and Space Flight

   


From time to time I work on engineering ideas that are aimed at increasing science return from robotic or human space flight.  Several examples include concepts to explore asteroids (PDF), concepts to explore the lunar poles (PDF, PDF), lunar sample return techniques (PDF), and illumination conditions at lunar polar landing sites (PDF).

Above (left to right): Press from Ciel et Espace and New Scientist magazines, illumination map of the lunar poles, and my concept to explore the lunar poles from a commonly proposed NASA landing site.