Scientists help recover gases from moon rock time capsule
Scientists from Washington University in St. Louis help recover gases from a lunar soil container that astronauts collected and vacuum-sealed on the surface of the moon in 1972. This effort is part of the initiative NASA’s Apollo Next Generation Sample Analysis (ANGSA). .
Apollo 17 astronauts Harrison Schmitt and Eugene Cernan collected the sample from the site of an ancient landslide in the moon’s Taurus-Littrow Valley. The astronauts used a coring device to dig out a column of lunar regolith – a coarse mixture of dust, soil and broken rock from the moon’s surface – and sealed it in a container. Back on Earth, NASA carefully placed the container in the lunar vault of NASA’s Johnson Space Center, where it remained in pristine condition, virtually untouched until now.
“For the past 50 years, the lunar core has been enclosed in a core sample vacuum container, which was then enclosed in an outer vacuum container,” said Alex Meshik, Physics Research Professor of Arts and Sciences. science and faculty member of McDonnell University. Space Science Center. “They were nested, almost like Russian dolls.”
The containers were placed in two sealed Teflon bags and stored in a nitrogen glove box in a vault.
Opening the containers, as Meshik and his collaborators did last month, was tricky. Scientists needed to be able to identify the original chemical signature of every bit of gas that might be in the containers. This includes lunar gas that may have been captured when lunar regolith was collected from the lunar surface, as well as any other gas that may have leached from the rocks over subsequent decades of storage.
“There is no perfect vacuum seal,” Meshik said. “There was no way of knowing how the container vacuum seals were performing after 50 years. Did they hold the vacuum? How well were they leaking? anticipate all possible scenarios so that we are ready for each outcome.
“For this reason, our device was designed to be able to perform not just a single gas extraction, but multiple extractions of different volumes under different conditions,” he said.
“To help us make informed decisions during these extractions, we have integrated into the device a mass spectrometer for real-time gas composition analyzes and three high-precision capacitive pressure gauges for non-destructive pressure measurements and independent of gas,” Meshik said.
Meshik led the design and construction of the extraction manifold apparatus, with support from Olga Pravdivtseva, associate research professor of physics, and Rita Parai, assistant professor of earth and planetary sciences, all in Arts and Sciences at the University of Washington. The three scientists are internationally renowned for their high-precision noble gas analyzes of terrestrial and extraterrestrial materials from various solar system bodies, including the sun itself (Genesis mission) and cosmic dust (Stardust mission).
Ryan Zeigler, NASA Apollo Sample Curator and University of Washington alumnus, received and also helped test the device at Johnson Space Center.
“Fifty years ago, when these samples were collected, NASA scientists had the foresight to put in place preservation procedures that would ensure future generations had access to pristine samples when new analytical methods and procedures would be available and new scientific questions would be asked,” said Brad Jolliff, Scott Rudolph Professor of Earth and Planetary Sciences and director of the McDonnell Center for the Space Sciences.
“At the University of Washington, we have several state-of-the-art labs that examine various aspects of these valuable samples and test hypotheses about their origins and how they fit into a modern planetary science context,” Jolliff said. , who is the Washington Institutional Principal Investigator. University within its ANGSA team, which is led by the University of New Mexico.
“The noble gas studies are a great example because they contain not only a lot of information about the current implantation of material from the sun to the surface of the moon, but also about the very origin of the moon four years ago. billion and a half years. Stay tuned for exciting results to come!”
Preliminary scientific results from the initial gas collection will be discussed at the Lunar and Planetary Science Conference, to be held in Houston March 7-11.
Moon gases from storage containers are now collected using the Extraction Collector Device. Once the gases trapped in the containers have been collected, the team plans to let other gases slowly diffuse out of the moon rocks themselves. NASA will then send the gases to selected laboratories in the United States and Europe that specialize in high-precision analyzes of oxygen, nitrogen, noble gases and organics, including the University of Washington. .
“One of the important features of 73001 (the NASA identifier for the particular lunar regolith sample from Apollo 17) is that it was taken at a depth that was always below zero for water,” Jolliff noted. “So the idea was that it could retain more volatiles than the upper part, which was subject to more daytime heating and cooling effects.”
As an experimental physicist, Meshik has a background in high-vacuum equipment and isotope mass spectrometry dating back to his university years in Russia, then at the Max-Planck-Institut für Kernphysik in Heidelberg, Germany, and finally at the Washington University.
He shared a personal reflection on the many hours of meticulous work spent assembling the extraction device with his wife and frequent collaborator Pravdivtseva:
“Building the device took place during the height of COVID restrictions, when we had to keep a six-foot distance between team members and work from home most of the time,” Meshik said. “We were limited to momentary outside contact with our EPS colleagues. During that time, the construction required more than two hands. Fortunately, the restrictions did not apply to married couples. has become our family business.”
Open a 50th birthday Christmas present from the moon
This effort is part of NASA’s Apollo Next Generation Sample Analysis (ANGSA) initiative.
Provided by Washington University in St. Louis
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