NASA has begun the arduous task of opening one of the last samples in existence from the Apollo 17 mission, collected nearly 50 years ago by astronauts. For half a century, the agency kept some tubes vacuum-sealed so that they could be studied years later using the latest technological breakthroughs with many new and exciting discoveries expected. Now, that time has come.
A satellite bearing the scars of the birth of the solar system
A desolate landscape, where dust and hue move in an alien-like fashion — our only natural satellite, the Moon, has fascinated humankind for eons. Scarred by tranquil seas of hardened lava and impact craters, some of which were formed over 3.8 billion years ago in the solar system’s early history, the moon is still as fascinating as ever.
Without an atmosphere to cause erosion and alter its landscape, the lunar surface remains frozen in time, leaving a record of a newly-formed universe accessible. When astronauts first dated the lunar surface and, coated with a thick layer of ‘moon dust’ known as regolith, the results were mind-shattering. The lunar samples were radioactively dated, showing ages varying from 3.3 to 4.4 billion years old – much older than most of the rocks on our planet, which have been continuously hidden or degraded by our atmosphere, tectonic activity, and weather. In fact, the rocks on the moon are so old that they offer a glimpse into the birth of the satellite, our very own planet, and even the solar system.
The Apollo missions to the Moon brought 2,196 rock samples back to Earth. NASA set aside two vacuum-sealed rock samples collected in 1972 by astronauts Eugene Cernan and Harrison Schmitt in the Taurus-Littrow Valley within Mare Serenitatis – the mission’s landing site, saving them for a better time.
Holding these samples and waiting on their analysis also coincides with NASA’s Artemis program hoping to send astronauts to the Moon in 2025. So officials determined now would be an excellent time to examine a sample from the Apollo 17 mission to pick up any findings the original researchers may have missed all those years ago when humans were last on the Moon, using our better technology and what we’ve learned from previous analyses.
Dr. Lori Glaze, NASA’s director of the Planetary Science Division, said in a statement that they predict “science and technology would evolve and allow scientists to study the material in new ways to address new questions in the future.” So what can we learn from the samples?
What we’ve learned so far about the lunar surface
Only a minuscule layer of gases exists on the lunar surface with no air to breathe. Like tiny cannonballs flying across the lunar surface unimpeded, they never collide as there are only 100 molecules of gas per cubic centimeter. To compare, Earth’s atmosphere at sea level has about 100 billion billion gas molecules per cubic centimeter, according to Space.com.
Several elements have already been detected on the lunar surface by various means. Detectors left by Apollo astronauts identified argon-40, helium-4, oxygen, methane, nitrogen, carbon monoxide, and carbon dioxide. Additionally, earth-based spectrometers have established the presence of sodium and potassium on the surface. At the same time, the Lunar Prospector Orbiter found radioactive isotopes of radon and polonium, and as recently as 2012, the Lunar Reconnaissance Orbiter detected helium.
Many of these gases are posited to come from the Moon’s interior, released by the bombardment of heavenly bodies smashing through its crust, releasing the hot lava below, flowing like lakes over its surface during the Moon’s infancy. More recently, studies have theorized that these extraterrestrial missiles caused ice deposition at the lunar poles and mixed with solar winds and moonquakes to leave behind non-native gases and compounds.
This is where the samples held at NASA’s Johnson Space Center in Houston come in. They’re dubbed the Apollo Next Generation Sample Analysis Program (ANGSA) 73001, and researchers have only just begun unsealing them, hoping to understand the lunar surface with up-to-date scientific instruments. Once there, they plan to mine the alien ice contained within its untouched mountains.
“Understanding the geologic history and evolution of the Moon samples at the Apollo landing sites will help us prepare for the types of samples that may be encountered during Artemis,” says Thomas Zurbuchen, NASA’s Washington Science Mission Directorate associate administrator.
“Artemis aims to bring back cold and sealed samples from near the lunar South Pole. This is an exciting learning opportunity to understand the tools needed for collecting and transporting these samples, for analyzing them, and for storing them on Earth for future generations of scientists,” Zurbuchen added in the official NASA press release.
How and where on the Moon were the samples gathered?
Cernan and Schmitt collected the 73001 samples using a hollow ‘drive tube,’ which they hammered into the lunar surface using a geology pick. The apparatus, a pair of connected, 14-inch (35-cm) tubes, were used to gather rocks and soils from a landslide which in itself is a mystery as there are no adverse weather conditions on the Moon or tectonic plates moving below the surface to cause one.
Hoping to solve this mystery with future knowledge, the bottom half of the drive tube was vacuum sealed on the Moon before bringing it back to Earth. NASA said only one other sample was collected under these conditions, making the collection process almost unique. The other tube (the top half of the drive tube) was plugged up to keep the contents intact and returned to Earth in a typical fashion where NASA teams analyzed it.
Now, attention is being focused on one of the two vacuum-sealed lower tubes, stored in a separate outer vacuum tube and kept in an atmosphere-controlled environment at Johnson for half a century. When it was collected, the lunar temperature below ground was freezing, meaning that volatiles (substances that evaporate at average temperatures, like water, ice, or carbon dioxide) might have been present. It goes without saying that the scientists are particularly interested in them as they will improve techniques to identify any volatiles missed in past research that the Artemis mission could then apply.
They already know that there won’t be much gas available. Still, NASA believes modern mass spectrometry technology may be able to analyze what is there, allowing the identification of unknown molecules if they’re present with the gas apportioned to different expert spectra facilities.
So how far along is the current ‘unsealing’?
In early February, the ANGSA team removed the outer protective tube establishing that no lunar gas was present: indicating that the sample held within the inner tube was stable and hadn’t leaked. Then on February the 23rd, scientists began a weeks-long process to pierce the main tube, harvesting the gas inside, without damaging the samples.
Rock samples will then be carefully extracted and disseminated between different scientific teams for analysis in the spring.
NASA’s Ryan Zeigler, Apollo sample curator, who is overseeing the project, says, “Once they get Artemis samples back, it might be nice to do a direct comparison in real time between whatever’s coming back from Artemis, and with one of these remaining unopened core, sealed cores.”
Accordingly, the experiment currently being conducted helps the world’s space community better prepare for the return of the Artemis mission team with large amounts of lunar gases and rocks.
The next major challenge for NASA
Another major challenge for space missions universally is moondust which stripped Apollo spacesuits threadbare. The dust is a significant problem as intense ultraviolet sunlight kicks electrons off particles in the lunar soil, giving those particles an electric charge that can keep them airborne for a long time. Ambient electric fields then lift the charged particles above the surface, forming a veil of dust kilometers high.
“It’s something we don’t see anywhere on Earth, and it’s something that has direct relevance to space exploration because if you understand how the dust behaves and is charged, you can prepare for moon exploration,” Dr. Denis Richard of NASA Ames, told Space.com. “Imagine if the dust is charged really, really strongly, you can have some trouble with space equipment, it can wear off your equipment because it’s abrasive,” he stresses.
When Apollo astronauts returned to Earth, still coated in it, they described moon dust as gritty, abrasive, and clingy, wreaking havoc on equipment and computers.
Therefore, much more will need to be learned about moon dust before humans return to the lunar surface; another reason for keeping 73001 in storage for so long is that it may contain something missed in the earlier, unsealed samples.
And once the world’s space agencies have deciphered the composition and mechanics of the jagged regolith, work can begin on next-generation spacesuits and equipment towards lunar colonization – heralding space travel for the masses and interstellar exploration. As NASA’s Ryan Zeigler says, “A lot of people are getting excited.” They’re right to be.