If all the Apollo 11 astronauts did was touch down and plant a flag, that would have been plenty. Fulfilling humanity’s dreams needs no peer review. But their contributions were scientific, too.
A still-operative set of mirrors left by Neil Armstrong about 100 feet from his famous footprint lets scientists ‘ping’ the moon with beams of light. By tracking photons that bounce back, they’ve made centimeter-scale measurements of the moon’s distance from Earth, and of variations in its orbit. They’ve even monitored fluctuations in the the universal force of gravity. (Good news: It’s very, very stable.) Instruments carried by Apollo 11 also measured solar wind and seismic activity. But perhaps the most compelling insights were geological, based on a box full of lunar rocks and some soil packed in by Neil Armstrong to keep the contents from bumping.
“When they came back, everybody was interested in the big rocks, but that soil, which was fine-grained stuff, is just a treasure trove,” said Randy Korotev, a University of Wisconsin lunar geochemist. “The moon is a recorder of things that happen in space that you can’t get from Earth.”
In 1969, Korotev was a graduate student in the laboratory of Wisconsin geochemist Larry Haskin. He watched the moon landing from his home in Green Bay, knowing that he’d soon study the rocks on his TV screen. Forty years later, he’s still studying them.
“We learned so much, just from that first mission. There was some first-order stuff that we didn’t understand. We had never seen stuff like this lunar soil that had been exposed directly to space for billions of years. The soil and some of the aspects of it were completely unknown,” he said. “We learned how old these basaltic dark spots were. It turned out they were 3 billion years old. It’s hard to find a rock on Earth that old, and when you look at them, it’s like they happened yesterday.”
“We learned about how the solar wind implanted ions into the soil from the sun,” he continued. “That’s the kind of stuff we never have on Earth, because the solar wind is absorbed by the atmosphere. People could study the cosmic ray tracks left when a cosmic ray hits a mineral grain. You can count the cosmic interactions in a cubic millimeter — and they are coming from outside the solar system. The list of things we learned is endless. It’s so endless that I can’t even begin to give everybody’s fields justice.”
Part of that list was contained in an issue of Science released on Jan. 30, 1970. It contains over 400 pages of research on Apollo 11 samples, and in commemoration of the landing’s 40th anniversary is now freely available in its entirety. (Among my favorite parts is the elegantly titled “Ages, Irradiation History, and Chemical Composition of Lunar Rocks from the Sea of Tranquillity,” and an advertisement for the J.T. Baker Chemical Company’s ULTREX Phosophorous Pentoxide, with “key trace metal impurities in the parts per trillion range.”)
Research on the Apollo 11 samples is still very much alive, said Korotev.
“There are types of measurements that we can make today that we couldn’t 40 years ago. The questions keep changing,” he said. “I’ve been doing this for 40 years, and I get excited every time I send a new batch of samples off to be analyzed.”
Note: Another fascinating document is the Apollo 11 Preliminary Science Report, published by NASA on Oct. 31, 1969. It describes the setup of the various experiments, and also contains an article entitled, “Crew Observations.” Its language is dryer than the “one giant leap for mankind,” but no less inspirational.
“The Apollo 11 mission offered us our first opportunity to observe directly the operational and scientific phenomena associated with landing on the lunar surface,” wrote Neil Armstrong, Edwin Aldrin and Michael Collins. “A large amount of fine lunar material appeared to be moved during the terminal phase of landin…. The path of this expelled material was parallel to the lunar surface, and the material seemed to travel at a great distance (over the horizon) at a high velocity.”
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