Opening Apollo 17's Last Sealed Moon Sample, 50 Years On

When Apollo astronauts brought samples home from the Moon more than 50 years ago, NASA deliberately left some unopened and untouched. Science and technology would move on, and future scientists should get to study these unique samples with new tools and laboratories. That became the Apollo Next Generation Sample Analysis initiative.

In the week of this episode of NASA Science Live, the team extracted the very last pristine core sample from Apollo 17 from its vacuum-sealed tube, in one of NASA's cleanest labs at Johnson Space Center — the agency's hub for extraterrestrial samples. Host Joy Ng talked to Juliane Gross, deputy Apollo curator; Jacob Bleacher, NASA's chief exploration scientist; and Andrea Mosie, Apollo sample principal scientist.

The full episode of NASA Science Live, Episode 42. Video from NASA

How the core was opened

The sample. It is the lower half of a double drive tube that astronauts hammered into the lunar surface, filling it with rock and soil. Because it came from deep and very cold ground, any trapped gases and volatiles could be kept, so it was sealed in a vacuum container on the Moon — and on Earth, placed inside another vacuum container.

The work began about three years earlier, with partners including the European Space Agency, the University of New Mexico and Washington University in St. Louis.

1. Catch the gas first. A piercing tool and a gas-extraction manifold were built for the job. When they came together in the lab, about seven weeks before the broadcast, the team pierced the container and drew the gas off into canisters to share with scientists.
2. Look inside. An X-ray CT scan — the same idea as a medical scan — gave a first look through the container. Good thing: the tube was overfilled, "a great problem to have," but it made the core very hard to push out. Gross and Mosie spent a week devising a new way to open it without losing any of the extra soil.
3. Open it. On the Monday of that week, they took the sample out — the first time anyone had seen it since it was sealed on the Moon.
4. Scrape. On Tuesday they shaved off the first millimeter of the surface, which had touched the tube, to expose soil that nothing from Earth has touched.
5. Shine light on it. Researchers from the University of Hawaii ran hyperspectral analysis: reading the light reflected off the core to see how its chemistry changes from top to bottom — and to check what orbiting spacecraft see in sunlight reflected off the Moon.
6. Dissect it. The slow part: a sample every half centimeter, to keep layers the eye cannot see, while recording grain sizes and colors and scanning larger fragments — all into a catalog from which researchers worldwide can choose.

For Andrea Mosie, in the Moon sample lab for 46 years, the difference was plain: the samples she handles daily have waited in the pristine sample vault for scientists to request them; this core had never been opened, seen or studied. Being first to see it "was awesome."

Why it matters for Artemis

Artemis is headed for the Moon's South Pole. There, with the Sun low on the horizon, some impact craters hold permanently shadowed regions that never see sunlight. Water — delivered perhaps by comets, or from inside the Moon — can be caught in these cold traps.

Bleacher called this core "almost like the first of the Artemis samples." The team wants to know how well the Apollo container kept the gases in, and whether anything from Earth leaked in. That shapes the tools to collect, contain and preserve polar samples — including, eventually, a real piece of lunar ice, which will need a whole system to keep it cold all the way to Johnson. Nobody yet knows whether that water is a little ice mixed with regolith, bigger chunks, or solid ice, or what other volatiles come with it.

Questions from viewers

Is a container closed on the Moon vacuum-sealed? Not automatically: lunar grains can sit in the gaps, and on Earth the far higher air pressure pushes in. A proper seal needs a soft metal gasket pressed into every nook — which this container had.

What does moon rock smell like? Nobody in the lab knows — samples are kept in Teflon bags in nitrogen and never sniffed. The astronauts, who took their dusty suits off inside their habitat, described a smell like gunpowder. The dust is still on the suits today.

Why sample a landslide? A landslide — like a crater, or a boulder that rolled downhill — brings material from farther away than astronauts can go, even on Apollo 17, whose lunar roving vehicle covered the longest distances of any mission. And this deposit lies near a fault, which, it was hoped, would carry gases from inside the Moon into it — one reason the core was vacuum-sealed.

What is possible now that was not then? CT scanning shows minerals and textures without harming a sample; mass spectrometers need less material for more precise data; and tiny amounts of gas can now be analysed.

Does the Moon have a core? Yes, though its size is debated. The Moon was once fully molten: heavy iron and nickel sank to form the core, light material rose to form the crust, and the mantle lies between — layers like Earth's, which is why scientists call it a planetary body.

What have earlier samples revealed? Soil from Apollo 11 held tiny white grains that could only have formed if the Moon had once been a giant ball of magma. That led to the idea of a giant impact between two protoplanets: the inner part formed Earth, and the debris circling it coalesced into the Moon.

Regolith also turned out to be nothing like Earth's dust. With no water or wind, grains stay sharp, almost like tiny pieces of glass, made as impacts shock, melt and shatter the surface. On later Apollo missions, with longer spacewalks, astronauts reported it irritating their eyes and lungs — so Artemis aims to keep dust out. And because nothing weathers it, the soil is an archive: it records the solar system's climate, how the Sun's output changed, and what struck the Moon — and probably Earth too.

How will Artemis collect samples? Mostly with Apollo's tried and tested tools — rakes, hammers, tongs, drive tubes — refined where they failed, such as dust in the gears.

Why bring rocks home at all? The best instruments can fill a room; the most detailed measurements happen on Earth.

What is it like to touch a moon rock? Nobody does. Curators work through the gloves of a glove box, and the samples are bagged in Teflon — you can feel the weight, not the rock. Hands carry particles and organics however well washed, and some researchers are looking for organic building blocks in lunar material.

How many samples will Artemis bring back? NASA thinks in mass — what a vehicle can lift off the Moon — not numbers. Visits may start at a week at a time, maybe once a year, growing to longer stays across more of the Moon.

Will Starship bring samples back? It is part of the path: for Artemis III, the Space Launch System and Orion take astronauts to lunar orbit, and SpaceX's Starship lander carries them down and back up.

Does it contain organic matter? Scientists prefer regolith to "soil," which on Earth means ground with organic material. Some team members look for organic compounds, which is hard: solar radiation sterilizes the surface, and any trace could be contamination. So each allocation ships with a witness foil — baked-out aluminum foil opened in the cabinet at the same time — to show what came from Earth.

Inside the lunar sample lab

• Apollo astronauts collected 842 pounds of lunar material, curated by NASA's Astromaterials Research and Exploration Science Division at Johnson Space Center in Houston, Texas.
• Samples are sorted by mission and stored in Teflon bags in nitrogen-filled cabinets, inside secure, environmentally controlled vaults.
• To enter, staff pass through a laminar-airflow change room and a minute-long air shower, and wear a full-body non-shedding polyester "bunny suit" and triple-layered gloves.
• Moon rocks may be touched only with Teflon, aluminum or stainless-steel tools, in dry nitrogen.

Advice for would-be curators

Find what gets you out of bed, both scientists said — NASA almost certainly has people who do it — and don't fear changing course. Bleacher, a geologist, now works mostly among engineers; Gross studied Earth geology through her PhD before turning to planetary science. Artemis will need engineers and scientists, but also people who bridge languages, medical experts to learn what dust does to the body, and artists and outreach staff.

Sources

Based on "NASA Science Live: We Just Opened a 50-year-old Moon Sample Episode 42]," hosted by Joy Ng, with Juliane Gross, Jacob Bleacher and Andrea Mosie, [NASA; a work of the United States government in the public domain. The source text is an automatic transcript; misheard names and words (such as "Artemus" and "£842" for 842 pounds) are corrected.