For the twentieth season, the LPI Summer Intern Program offers selected undergraduate students the opportunity to participate in lunar and planetary science research at the Institute and the NASA Johnson Space Center. The 1996 program begins June 10 and ends August 16.

When the program was conceived 20 years ago, its objectives were "to provide bright undergraduates with interests in lunar and planetary science with opportunities to experience full-time research in the field of their choice, to present the results in written and oral form, to meet active researchers who can help them assess the future of the research field, and to evaluate research as a career choice."

Through 1996, 256 students representing 159 universities across the United States and abroad have participated in the program, and many have chosen careers in planetary science. In 1995 alone, 35 former interns gave presentations at the annual Lunar and Planetary Science Conference.

For more information or to apply for internship next year, contact LPI Summer Intern Program, 3600 Bay Area Boulevard, Houston TX 77058-1113. Information can also be found on the World-Wide Web at URL:

This summer's interns will work on the following projects under the guidance of their advisors at LPI and JSC.

KATHERINE HERRELL, University of Texas
Advisor: Graham Ryder, Lunar and Planetary Institute

"Apollo 15 Mare Basalts." In this project the intern will classify olivine on the basis of shape and zoning and will make size measurements in a study aimed at clarifying the conditions of olivine crystallization. The study will be made on thin sections of about 20 Apollo 15 olivine-normative basalts in the advisor's possession using the microscope at the Lunar and Planetary Institute. The intern will first photograph the sections. Then she will classify the olivines according to shapes and other morphological features that provide information about crystallization conditions, including growth, reequilibration, and resorption. The size distribution of olivine crystals will be assessed, and comparisons within and among samples will be made. The intern will select some olivine crystals from several samples for microprobe analysis that will be made using facilities at the Johnson Space Center. These analyses of the variations in composition will provide further information about growth, reequilibration, and resorption. Some comparison will be made with data available for terrestrial basalts of known origin; if time permits, some microscope comparison with such basalts, e.g., samples from Hawaiian lava lakes, will be included in the study. Instruction will be provided by the advisor on all techniques and aims.

MARK JOHNSON, Bridgewater State College
Advisor: Carlton C. Allen, Johnson Space Center

"Lunar Dark Mantle Deposits." Violent volcanic eruptions on the Moon have produced large deposits of microscopic glass particles. Last year's intern analyzed laboratory spectra of three glass types, as well as representative lunar soils, to demonstrate how the glasses could be distinguished using data from the Clementine filter passbands. The 1996 intern will use Clementine images to create pseudocolor maps of several large volcanic deposits. He will then locate areas of relatively pure colored glass within the larger deposits and characterize these areas using Apollo orbital photography. Most importantly, the intern will attempt to correlate the colors measured by Clementine with laboratory spectra of lunar samples and analogs in order to estimate chemical composition.

KEVIN JONES, College of William and Mary
Advisor: Paul Schenk, Lunar and Planetary Institute

"Topography on Io." Io is the most volcanically active object in the solar system, yet we know little about even the gross composition of the lavas that cover the vast majority of the surface. The intern will, with guidance, be responsible for selection of areas to be examined in detail, based on geologic significance and data availability. Landform types will be classified prior to data analysis. Stereo images will be produced and utilized where available to determine heights and slopes as a function of location on the surface and feature type. Experience in image processing techniques will be gained, using methods already tested and assisting in the further development of recently acquired methods. These data will then be useful for later integration into lava flow models and the physical volcanology of Io. A database will be developed that will complement, and not be superseded, by Galileo. Hoped-for compositional constraints from Galileo will ultimately permit detailed physical volcanology to be used together with these data to understand Io's volcanic history and nature.

KENTARO KANEDA, University of Tokyo
Advisor: Gordon McKay, Johnson Space Center

"Zoning in Nakhla Pyroxenes." This project will be a detailed elemental mapping study of Nakhla cumulus pyroxenes and of pyroxenes from crystallization experiments on proposed Nakhla parent compositions. Elemental maps will be collected using the Cameca SX-100 electron microprobe and will be studied using various image processing techniques to enhance and quantify the zoning patterns. Crystals in the proper orientation to reveal sector zoning will be located and zoning patterns will be studied. Results will provide important constraints on the origin of the Al variations in Nakhla pyroxenes and, ultimately, on the composition of the melt from which those pyroxenes crystallized.

PETER LETH, Pomona College
Advisor: Allan H. Treiman, Lunar and Planetary Institute

"Mars Valley Geology." Much of the geology of Mars is inferred from surface landforms, as imaged from the Viking Orbiter spacecraft. Canyon walls provide one of the few possible places to view the geology beneath the landforms. Reull Vallis is such a canyon and affords a unique view beneath martian highlands. Using spacecraft imagery, we will map part of the Reull Vallis area, emphasizing geological deposits and structures exposed in the Vallis walls. From stereo images, we will construct topographic profiles across and along Reull Vallis (and possibly a digital topographic map) to determine elevations, slopes, and thickness of deposits. Integrating these data, we will try to understand what rock types are exposed in Reull Vallis. Finally, we will compare our results with regional and global outlines of the geology of the martian highlands.

CELINDA MARSH, University of Texas
Advisor: Robert R. Herrick, Lunar and Planetary Institute

"Venus Volcanos." Kunhild (18 N, 91 E) and Ereshkigal (21 N, 85 E) coronae on Venus are two volcanic structures that superficially have morphologic and topographic signatures similar to other large shield volcanos on Venus, particularly those of Central Eistla Regio and Bell Regio. However, unlike those volcanos and almost all other large volcanos on Venus, Kunhild and Ereshkigal have negligible signatures in the global gravity field. One possible explanation is that these are rare examples of extinct volcanos on Venus. If these are relatively old, dormant volcanos it would contradict the notion that large shield volcanos are a very recent phenomenon indicative of a thickening global lithosphere. The intern will perform a detailed study of the surface morphology to learn about the region's geologic history and possible causes of its unique geoid signature. She will do morphologic mapping to determine the sequence of emplacement of various surface features. The two volcanos are located in a region with radar stereo coverage, which will be used to develop a topographic model with 1-km horizontal resolution to aid the analysis. In particular, the topography can be used to determine whether any post-emplacement tectonic tilting has occurred for various lava flow units.

PIMOL MOTH, University of California at Berkeley
Advisor: Deborah Domingue, Lunar and Planetary Institute

"Galilean Satellite Spectra." The three icy satellites of Jupiter are in a dynamic environment. They reside within the large magnetic field of Jupiter, which rotates more quickly than the satellites orbit the planet. Thus their trailing hemispheres are exposed to ion bombardment that their leading hemispheres do not experience. Sulfur ions from the magnetosphere are hypothesized to have been implanted in Europa's water as crust. Ultraviolet observations by Lane et al. (1980) have detected the presence of SO2, which may be the by-product of this implantation. More recently, Calvin et al. (1995) and Noll et al. (1992) have detected possible oxygen implantation products on Ganymede. This April an observation will be made of the icy Galilean satellites with the International Ultraviolet Explorer (IUE) in an effort to examine their UV spectra for evidence of additional ion implantation products. A comparison will be made of our spectra with decade-old IUE spectra to look for temporal changes in the surfaces of these satellites. This project will involve reducing the IUE spectra obtained and examining them for implantation product signatures in addition to comparing them with the decade old dataset for temporal changes.

KIEKO NAKAMURA, Kobe University
Advisor: Michael E. Zolensky, Johnson Space Center

"Dark Inclusions in CV3 Chondrites." Using optical microscopy, scanning electron microscopy (SEM), and transmitted electron microscopy (TEM), the intern, with assistance, will produce detailed mineralogical characterizations of dark inclusions from CV3 chondrites. This work will shed additional light on geological processes that occurred on the parent asteroids.

CRAIG PAMPLIN, University College of the Cariboo
Advisor: Richard V. Morris, Johnson Space Center

"Acid-Sulfate Weathering." A detailed chemical analysis for sulfur in Mauna Kea tephra will be carried out. This data will better define the mineralogy of sulfur-bearing phases and define the origin of the sulfur, which is important for defining the jarosite formation processes on Mauna Kea and, by inference, on Mars. The sulfur could come from either magmatic gases or sulfide minerals. The project will involve analysis of approximately 100 samples and synthesis of the results with other data to give a model for acid-sulfate weathering processes on Mauna Kea.

PATRICK RUSSELL, Williams College
Advisor: Gary E. Lofgren, Johnson Space Center

"Relict Chrondrules." The study of recycling of chondrule material during chondrule formation is an important new area of interest. Recent studies have shown that relicts of early chondrule-forming events are more common in chondrules than previously thought. An extensive experimental study of the kinetics of recycling material to place new constraints on the formation process has been started. The intern will gain hands-on experience with conducting the experiments and examining the results; the most important factors to be determined by experiment are the rate of destruction of relict materials during the heating event and the overall time constraints that can be placed on the duration of the chondrule-forming event. In addition, the intern will examine thin sections from the meteorite collection to find examples of relict materials in chondrules for comparison with the experimentally produced relict textures.

AMER SMAILBEGOVIC, College of Charleston
Advisors: Donald A. Morrison, Johnson Space Center and Paul D. Spudis, Lunar and Planetary Institute

"Lunar Far Side Basins." The Clementine mission has provided us with multicolor images and topographic data for the Moon. In this project, the intern will collect and process color image data for the ejecta blankets of large impact basins on the Moon. These data will permit the mapping of compositional differences within and among ejecta for a variety of basin sizes and ages. Topography from the laser altimeter will allow crater and basin volumes to be estimated. By examining the composition of ejecta and using estimates of basin volumes and excavation models, we can reconstruct the targets of the basins and examine the compositional and petrologic structure of the ancient lunar crust. The intern will learn the techniques of image processing and photogeological mapping and will integrate lunar sample and geophysical information into a refined model of the structure and evolution of the Moon's crust.

ANNE TAUNTON, University of Arkansas
Advisor: David S. McKay, Johnson Space Center

"SEM Studies of Microbes." A major goal of the exploration of Mars is to determine whether life has developed there. To help understand how potential martian life may have evolved and whether such life might still exist in extreme environments on Mars, we will study selected samples from extreme environments on Earth. Samples of microbes are known to grow in rocks in Antarctica, in hot springs, in highly saline evaporate lakes, in arid deserts on rock surfaces, and deep in the Earth in rocks at depths of 10 kilometers or more. The intern will study representative samples of each of these materials with the scanning electron microscope (possibly supplemented by TEM studies of selected samples) to characterize the morphology and chemistry of the microbes, document the microbe-mineral interactions, and determine the types of fossil preservation, if any. Using published data and papers, the intern will also make a parallel evaluation of Mars environments in terms of their potential to sustain microbial life.