While on the Moon’s surface, Aldrin deployed instruments to measure the distance from the Moon to the Earth, as well as to analyze the chemical composition of solar wind and the to measure the Moon’s seismic activity. Courtesy of NASA
On July 20, 1969, Neil Armstrong became the first person to step on the Moon’s near-black, powdery surface as an estimated 600 million people back on Earth watched the historic moment live on television.
The summer of 2019 marks the 50th anniversary of the Apollo landing, which fulfilled President John F. Kennedy’s ambitious goal, set in 1961, to land a crewed spacecraft on the Moon and return to Earth. Apollo 11, which included Armstrong, Michael Collins, and Edwin “Buzz” Aldrin, achieved this feat in just over eight days, traveling a total of 953,054 miles.
The journey—and live audio and video transmission, courtesy of a custom low-light camera from Westinghouse Electric’s Aerospace Division—was an astounding technological achievement. But the scientific results and specimens from Armstrong and Aldrin’s 21-hour-and-36-minute stay on the Moon produced invaluable data and fueled research long after the mission was over.
“The Apollo 11 mission provided an enormous sense of excitement and accomplishment to Americans at the time,” says Curator Michael Shara, who oversaw the 2010–2011 exhibition Beyond Planet Earth: The Future of Space Exploration. “Even though the mission was completed 50 years ago, amazingly it’s still bearing fruit. What Apollo taught us has given us a far better understanding of the origins of the solar system.”
Lunar Experiments
After the Lunar Module landed on the Moon’s Sea of Tranquility, Aldrin and Armstrong conducted a series of landmark scientific experiments. Aldrin deployed the Early Apollo Scientific Experiments Package (EASEP), which included instruments for several tests to be left on the lunar surface. The Passive Seismic Experiment contained seismometers to measure moonquakes or effects of meteoroid and other impacts on the Moon. The Laser Ranging Retroreflector allowed for a precise measurement of the distance between Earth and the Moon, obtained by timing how long it took for a laser beam to travel from Earth to the lunar surface and back.
Another experiment, created by Swiss scientists, collected solar-wind particles so that researchers could analyze the composition of solar wind. The team also recorded extensive observations of the lunar surface, photographed the terrain and each other, and gathered 22 kilograms of rock, soil, and dust samples—all in the course of approximately two hours.
Lasting Legacy
The observations and material collected by the Apollo 11 crew led to exciting discoveries. Among the most important findings: analysis of the chemical composition of lunar rocks helped strengthen the theory that the Moon was actually a chip off the young Earth.
Researchers now think that soon after the formation of the solar system, Earth was struck by a Mars-sized object, intimately mixing the two bodies. Some of the resulting vapor and rock later congealed into the single satellite that is our Moon today. This origin story would explain why the Moon doesn’t have a large iron core and is mostly composed of materials found in Earth’s crust, and why the ratios of many isotopes on the Moon’s surface are identical to those found in rocks on Earth. “It was a stunning finding,” says Shara.
One of the instruments left on the Moon’s surface—the Laser Ranging Retroreflector—allowed scientists to collect data for decades after Apollo 11’s return to Earth. Findings include that the Moon is moving farther away from Earth and that the universal force of gravity is stable.
Research based on materials gathered during the Apollo missions continues to this day.
“The specimens collected 50–100 years ago—like the Museum’s dinosaur specimens—are still being analyzed today and giving us new information.”
In March 2019, NASA announced that it would open a previously unstudied cache of Moon rocks and a sedimentary core from the Apollo missions for study. “Samples were deliberately saved so we could take advantage of today’s more advanced and sophisticated technology to answer questions we didn’t know we needed to ask,” said Lori Glaze, acting director of NASA’s Planetary Science Division in Washington, D.C.
“With very few exceptions, no other scientific expedition is still producing this much new science,” adds Shara. “It’s a great example of the value of unique and rare specimens that exist in collections like those found here at the Museum—that you can go on studying them for a long time. The specimens collected 50–100 years ago—like the Museum’s dinosaur specimens—are still being analyzed today and giving us new information. These Moon rocks have not yet given up all of their secrets, and they likely still won’t 50 years from now.”
Moon Rocks at the Museum
About three months after Apollo 11 returned to Earth, in November 1969, the Museum received a special delivery from NASA: a glass dome filled with nitrogen, with a lunar rock inside.
According to The New York Times, the timing of the arrival hadn’t been shared with the Museum, and when the specimen was delivered on Saturday morning, a makeshift display case had to be arranged. The following day, “a tiny piece of the Moon drew the largest crowd in the 100-year history of the American Museum of Natural History,” the paper reported: 42,195 people, or three times the size of the regular Sunday crowd. The Museum soon organized a more elaborate display case with educational materials and magnifying glasses for the Moon rock’s two-and-a-half month stay.
Today, the Museum is home to four Moon rocks collected during the Apollo lunar missions, though none from Apollo 11. On the first floor of the Rose Center for Earth and Space, near the entrance to the Hayden Planetarium dome, visitors can see a basalt sample collected on the lunar surface by astronauts David Scott and James Irwin on the Apollo 15 mission. More Moon rocks are on view in the Ross Hall of Meteorites, including two samples of mare basalt from the Apollo 14 and Apollo 17 missions and an Apollo 16 sample of anorthosite breccia, formed by fragmented rock that was fused together by the pressure and heat of an asteroid impact.
“The Apollo program was the beginning of a great age of exploration,” says Denton Ebel, curator in the Division of Earth and Planetary Science who oversaw this year’s update to the Ross Hall of Meteorites, which reopens this month with new exhibits about specimen-retrieval missions to asteroids. “Sample-based science is entering a whole new phase.”
For a different kind of artifact from the 1969 Moon landing, visitors can peruse the photo exhibit Full Moon: Apollo Mission Photographs of the Lunar Landing in the Rose Center for Earth and Space. The exhibit features digital reproductions from NASA’s photographic archive—including Aldrin’s shot of footprints in the soil of Mare Tranquillitatis.
Back to the Moon
While NASA has not returned to the surface of the Moon since 1972, it has sent missions to farther destinations in the solar system, including Mars, Saturn, and asteroids like Bennu. That has left a vacuum in lunar exploration that other nations are beginning to fill.
In January, China succeeded in landing a robotic rover on the Moon’s far side, in the largest-known impact crater in our solar system, the Von Kármán crater. Scientists think the far side’s rocks preserve important clues about the early solar system. The mission also carried plant seeds that successfully sprouted, and while the seedlings didn’t live long, the mission was the first ever to grow organic matter on the Moon. China’s future goals include locating ice deposits on the far side, setting up a lunar base, and putting astronauts on the Moon within 10 years.
“At some point humans are going back,” says Shara. “And whoever gets there first will spur the others. There’s great astronomy to be done there in future.”
A version of this story appeared in the Summer 2019 issue of Rotunda, the Member Magazine.