#LPSC2018: An Apollo 17 session with moonwalker Jack Schmitt
The Lunar and Planetary Science Conference (LPSC) is held each year in The Woodlands, a town about an hour north of Houston, Texas. Almost two thousand planetary scientists attend the conference, and session topics range from Mercury out to Pluto, with titles such as "Space Weathering is Ruining Perfectly Good Planetary Surfaces Across the Solar System" and "Tectonics and Dynamics: Crunchy Outside, Chewy Inside". The light-hearted spirit of LPSC is present every year, but this year's conference was particularly special due to two special sessions commemorating the 45-year anniversary of the Apollo 17 mission.
The Apollo 17 mission, which occurred from December 6th through 19th, 1972, was the last mission of NASA's Apollo program. Two astronauts traveled to the Taurus-Littrow Valley on the Moon, which is located in the northeastern quadrant of the side that always faces the Earth. The astronauts brought back over 240 pounds of lunar samples and carried out numerous experiments on the lunar surface, including seismological, electrical, and heat flow measurements. The samples that they collected and the instruments that they set up have spawned countless scientific advances, and a select few of these advances were the focus of the two Wednesday sessions at LPSC: "Taurus-Littrow Valley: 45 Years after Apollo 17". The afternoon session had talks falling into three main categories: science done with specific Apollo 17 samples from the Taurus-Littrow Valley, science done using the instruments that the astronauts set up at the landing site, and public outreach and engagement.
Apollo 17 LPSC session poster
A poster outside the conference room showing the three Apollo 17 astronauts. Harrison “Jack” Schmitt, pictured on the far left, is the only geoscientist to have walked on the Moon. He was in attendance at the Wednesday afternoon session on the Taurus-Littrow Valley at LPSC, where he was very engaged with the speakers: he asked questions after nearly every talk.
The first section of the session focused on science done using specific Apollo 17 samples and how the samples have been used to constrain the geology of the Taurus-Littrow Valley and the Moon in general. Dr. Clive Neal of the University of Notre Dame talked about how the samples collected during Apollo 17 consist of both basalts and volcanic glass. Both of these categories have been further divided into subcategories, each describing a specific property or process unique to a group of samples. Dr. Stephen Elardo of the University of New Mexico focused on the Mg-suite rocks: an unusually large group of samples that can be used to constrain lunar chronology and record alteration processes throughout the Moon's history. The Mg-suite samples that the Apollo 17 astronauts collected are not native to the Taurus-Littrow Valley; they were excavated by the impact that created the Imbrium basin.
Dr. Chip Shearer, also of the University of New Mexico, talked about the mechanisms of sample collection itself. The Apollo 17 astronauts sealed samples while on the lunar surface, and some of these samples have yet to be opened. How we treat these samples, as well as how the vacuum systems to contain these samples performed, will inform sample return procedures in future missions. Dr. Ian Garrick-Bethell of the University of California Santa Cruz made the case for why Apollo 17 sample 76535 was excavated by the impact that created the extremely large South Pole Aitken basin, and was then delivered to the Taurus-Littrow Valley in a second impact, where it was then collected by the Apollo 17 astronauts.
And lastly, a talk given by Smith College undergraduate Brenna Getzin about her summer work at MIT presented perhaps the first evidence for the direction of the Moon's ancient magnetic field. After her presentation, Getzin said, "It was not only an incredible experience to talk alongside so many incredible scientists, but to be able to report new results with Jack Schmitt sitting in the front row–who actually whacked my sample off of a boulder on the Moon!–was such an honor. That is one incredibly brave geologist!"
Schmitt at Shorty Crater
Harrison “Jack” Schmitt, one of the two people to walk on the Moon and an attendee of the Wednesday session on the Taurus-Littrow Valley at LPSC, overlooks Shorty Crater next to the lunar rover.
The second group of talks in the session focused on the science done by some of the instruments that the Apollo 17 astronauts set up on the lunar surface. Dr. Renee Weber of NASA Marshall Space Flight Center presented on thermal moonquakes: small tremors that occur near the lunar surface most often at sunrise or sunset (remember that lunar sunrise and sunset occur once a month, as seen by us on Earth!). Dr. Robert Grimm of the Southwest Research Institute focused on the Apollo 17 Surface Electrical Properties (SEP) experiment, and how modern computational methods have been able to improve the analysis of the original SEP data that was limited by scarce analysis and reporting.
Dr. Seiichi Nagihara from Texas Tech Univeristy and Dr. Matt Seigler of the Planetary Science Institute each had a talk on the Apollo heat flow experiments. The Apollo 17 heat flow instruments were the second set of such instruments on the Moon; the first set was installed during the Apollo 15 mission. The differing location of the two sets of instruments showcases some large-scale differences in the Moon's heat flow: the Apollo 15 measured heat flow value was 30 percent larger than the Apollo 17 value, most likely due to Apollo 15 being in a region with more heat-producing elements in the lunar crust.
Finally, the last two talks in the session were focused on the public engagement with the Apollo 17 data and how this data can be used in the future for both scientific and public purposes. Ben Feist of Jacobs Technology Inc. focused on a project to collect of all the Apollo 17 data (photos, transcripts, videos, audio, everything!) on one site. Because Apollo 17 is the one of the best-recorded sets of geologic field experiments, it will serve as an example for future missions to the Moon and to Mars. This focus on the Apollo 17 mission means that its data must be intelligently stored and easily accessible. This is accomplished by a common temporal thread between all items and an intuitive user interface. Check out apollo17.org to see for yourself how they have organized all of the mission data!
And lastly, Michayal Mathew, an undergraduate in the department of Aerospace Engineering at Texas A&M University, showcased his development of a virtual reality (VR) environment simulating the Apollo 17 landing site. The VR environment, impressive in its scope and its detail, was a product of his summer internship at NASA Goddard Space Flight Center. The VR simulation of the Taurus-Littrow Valley represents an intuitive and natural way to present the data that was collected by the mission. Mathew emphasized that VR is an indispensable tool for engagement with scientific data sets, not only for scientists but also for those of us who may never get the chance to be an astronaut and walk on another planetary body.
For further information on the Taurus-Littrow Valley session at LPSC, click here for a link to the schedule with links to individual abstracts. For information on the rest of the LPSC session, click here for the complete program.
Editor's note: Here's a video of a panel discussion with Schmitt that happened after the session!