Dr. Paul D. Spudis

Planetary Geology and Remote Sensing

I am a geologist interested in the geological history and evolution of the Moon and the processes of impact and volcanism that have shaped its surface. I study the Moon largely by remote sensing, whereby composition and physical properties are determined through analysis of data returned by orbiting spacecraft and from Earth-based telescopic sensing. I combine this information with data from photographs and lunar samples obtained by the manned Apollo missions to reconstruct the nature, composition, and history of the Moon. Because impact and volcanism are the principal processes that have shaped the Moon and other terrestrial planets, I study impact craters and lava flows on the Earth as guides for interpreting planetary histories. The Dept. of Defense Clementine mission to the Moon, for which I was Deputy Leader of the Science Team, mapped the Moon's topographic shape and surface color in the visible and near-infrared parts of the spectrum (where information on mineral composition can be extracted). My current research largely focuses on analysis and comprehension of the huge quantity of data (more than 60 Gbytes!) returned by this mission. By integrating this new, global dataset with the information provided by the Apollo samples, we will be able to reconstruct the structure and history of the Moon, a complex and fascinating planetary object as well as our nearest neighbor in space.

Clementine Mission Data:

I was the Deputy Leader of the Clementine Science Team in 1994. We are conducting several interesting studies of the Moon using Clementine mission data. You can see the results of some of these studies (and download the images and global maps) by following this link:


We have also prepared a set of 20 35mm color slides, showing some of the most dramatic images returned by Clementine and prepared from its mission data. You can see these slides (and read the accompanying captions) at the following link:


This slide set (and others) can be ordered (at cost) directly from the LPI:

Order Dept
.Lunar and Planetary Institute
3600 Bay Area Blvd.
Houston TX 77058
(281) 486-2172

You may also be interested in the following Clementine links, as well:

For a general description of the Clementine mission (and for the exploration of the Moon in general), see:


For more downloadable Clementine images, check out:


Really beautiful image products, produced by the image wizards at the USGS-Flagstaff.


The official NASA data center page, including information on how to order your own personal set of the complete mission data archive (almost 90 CDís!!)


The original Naval Research Laboratory site (NRL built and operated the Clementine spacecraft), including a really cool image browser (where you point and click your way to any lunar surface feature or area you may be interested in).

A New Book on the Moon!

My new book, The Once and Future Moon, published by the Smithsonian Institution University Press, is written for the general public and includes the very latest Clementine mission results.

This book describes the history of manís study of the Moon, Earthís nearest neighbor in space. I first describe the observation of the Moon by telescopes and spacecraft and the history of the Apollo explorations. I next cover the materials that make up the Moon and its geological history, based on the samples, photographs, and remote-sensing data. I include in this synthesis both Apollo data and data from the 1994 Clementine global mapping mission. In the final chapters of the book, I describe the four reasons to explore and use the Moon, steps in lunar exploration (including the types of missions needed to establish a lunar outpost), and finally, I assess the near-term future of the space program and where the Moon fits into a long-term strategy of space exploration. A series of detailed appendices give basic data about the Moon, a history of lunar exploration, detailed glossaries of people, places, and things dealing with the Moon, and a comprehensive and annotated bibliography of books, maps, and videos. The book is copiously illustrated with over 100 black and white photographs and line drawings and over 20 full color plates.

You can get this book now at your local bookstore (if not on the shelves, they can order it for you) or you can order it yourself directly from the Smithsonian Institution Press (telephone: 800-782-4612). The hardcover book costs $29.95

Ice on the Moon!

Our most recent paper on the Clementine results was published in the 29 November issue of Science magazine, discussing the results of the bistatic radar experiment. In this experiment, we used the spacecraft radio transmitter to study the surface properties of the permanently dark areas near the south pole of the Moon (see the LPI-Clementine page above). Results indicate that ice occurs in these areas! You can read about this astonishing result in the original (rather technical) article:


Or, in archaic hardcopy in the 29 November, 1996 issue of Science magazine:

Nozette, S., Lichtenberg, C.L., Spudis P.D., Bonner R., Ort W., Malaret E., Robinson M., and Shoemaker E.M., The Clementine bistatic radar experiment. Science 274, 1495-1498, 1996.

I have also written a brief summary of this discovery for the general reader. You can find this internet publication at:


This online article includes several color graphics illustrating the geology of the south pole and a map of the suspected ice deposits.