When Neil Armstrong set foot on the moon on July 20, 1969, the pictures sent to Earth captured a historical moment: It was the first time that any human set foot on another body in our solar system. Fifty years later, experts are debating how to preserve humankind’s first steps beyond Earth. Could a National Park on the moon be the solution to saving Armstrong’s bootprints for future archaeologists?

Flags, rovers, laser-reflecting mirrors, footprint—these are just a few of the dozens of artifacts and features that bear witness to our exploration of the moon. Archaeologists argue that these objects are a record to trace the development of humans in space. “Surely, those footprints are as important as those left by hominids at Laetoli, Tanzania, in the story of human development,” the anthropologist P.J. Capelotti wrote in Archaeology. While the oldest then known examples of hominins walking on two feet were cemented in ash 3.6 million years ago, “those at Tranquility Base could be swept away with a casual brush of a space tourist’s hand.”

Fragile Traces

Just how fragile humankind’s lunar traces are was seen already during Apollo 12. On November 19, 1969, Charles “Pete” Conrad and Alan Bean manually landed their lunar module in the moon’s Ocean of Storms, 200 meters from the unmanned probe Surveyor 3, which was left sitting on the moon’s surface two years earlier, in 1967. The next day, Conrad and Bean hopped to Surveyor 3. As they approached the spacecraft, they were surprised: The spacecraft, originally bright white, had turned light brown. It was covered in a fine layer of moon dust, likely kicked up by their landing.

Without Apollo 12 upsetting the moon dust, Surveyor 3 would likely have remained stark white. Unlike Earth, the moon has no wind that carries away the dust, no rain to corrode materials, and no plate tectonic activity to pull sites on the surface back into the moon. But the moon’s thin atmosphere also means that solar wind particles bombard the lunar surface, and harsh ultraviolet light has likely bleached the U.S. flag bright white. The astronauts’ first bootprints will likely be on the moon for a long time, and will almost certainly still be there when humans next visit—unless, by tragic coincidence, a meteorite hits them first. Had LunaCorp not abandoned the idea in the early 2000s, the company’s plan to send a robot to visit the most famous sites of moon exploration could have done a lot of damage. And with Jeff Bezos’ recent unveiling of a mock-up of the lunar lander Blue Moon, it is only a matter of time before corporate adventurers and space tourists reach the moon.

Historians and archaeologists are keen to avoid lunar looting. Roger Launius, senior curator of space history at the National Air and Space Museum in Washington, D.C., warned: “What we don’t want to happen is what happened in Antarctica at Scott’s hut. People took souvenirs, and nothing was done to try to preserve those until fairly late in the game.” On the other hand, there is a legitimate scientific interest in investigating how the equipment that’s on the moon was affected by a decades-long stay there.

But how to preserve and protect human artifacts on the moon? In 1999, the anthropologist Beth O’Leary, with the Lunar Legacy Project, proposed that Tranquility Base become a National Historic Landmark. As a first step, the group of archaeologists, curators, and physicists documented artifacts in Tranquility Base for a preliminary archaeological site plan. However, when O’Leary approached NASA, she was rebuffed: “taking steps to preserve it would be perceived as a U.S. claim of sovereignty over the Moon,” according to Roger Launius, a former NASA chief historian.

All attempts to protect sites on the moon have to grapple with space law. At the height of the Space Race, in 1967, the Outer Space Treaty was drafted, ratified, and came into force. “Both the United States and the Soviet Union feared that the other nation would claim sovereignty over a celestial body such as the moon, place weapons there, and exclude the other from those same privileges by virtue of being first,” Kyle Ellis writes in the Fordham Environmental Law Review. The treaty prohibits states from owning territory on the moon. “Space junk,” however, continues to belong to the state that sent the craft or equipment into space.

This leaves space custodians with a conundrum, writes Capelotti (the anthropologist). “If the U.S. owns the archaeological remains of Apollo 11 but not the ground underneath it, how to protect the former without disturbing the latter? Does America own Neil Armstrong’s famous first footprints on the Moon but not the lunar dust in which they were recorded?”

Artifacts in Orbit

In 2011, NASA issued guidelines for how missions to the moon should avoid crashing into artifacts or spraying rocket exhaust onto historic sites. These guidelines include no-fly zones over the landing sites of Apollo 11 and Apollo 17, and boundaries to how close rovers approach landers.

But these are, for the moment, just recommendations. In 2010, efforts by O’Leary led to the listing of objects and structures at Tranquility Base on the California and New Mexico State Registers of Cultural Properties. In 2013, a bill introduced to the House of Representatives, The Apollo Lunar Landing Legacy Act, proposed to preserve all six Apollo landing sites as National Historical Parks, seeking World Heritage Site status for the Apollo 11 landing area.

But this bill also stood in contradiction with existing space law, and failed. “Although the bill acknowledges treaty obligations of the United States, it would create, in effect, a unilateral U.S. action to control parts of the Moon. …It is legally flawed, unenforceable, and contradictory to our national space policy and our international relations in space,” wrote Henry Hertzfeld and Scott Pace in an article in Science. A new bill, the One Small Step to Protect Human Heritage in Space Act, introduced in the Senate in May, tries a different approach, requiring all U.S.-licensed missions to adhere to NASA’s guidelines from 2011.

But the moon is only the beginning: There are tens of thousands of objects are circling the Earth. Vanguard 1, the first and oldest man-made object in orbit, has traveled around the Earth more than 200,000 times. The archaeologist Alice Gorman argues that this sort of “space junk” should be managed as heritage, since it offers unique insights into human development. “Early telecommunications satellites, for example, are the artifacts that created the modern world,” she said in an interview.

Gorman wants to save defunct satellites and spacecraft in orbit. She argues that spacecraft that represent a nation, including early satellites from Indonesia, or the first geosynchronous satellite, should be saved. “This is a cultural landscape, and removing parts of it will destroy the relationships within it,” she said.

Back into Space

The Outer Space Treaty was modeled after the Antarctic Treaty. Taking a deliberately multinational approach, it recognizes that space should be explored and used for the benefit of all humanity. The failed attempts to save our bootprints on the moon, on the other hand, all focused on the U.S. Although the provisions of the One Small Step Act only apply to U.S.-based missions, the bill addresses the need to bring other nations on board. “It is the sense of Congress that the President should initiate a diplomatic initiative to negotiate an international agreement,” the bill reads.

Even though it was U.S. citizens who left their bootprints on the moon, protecting them needs to be an international effort. It only takes a careless brush of a space tourist’s hand to disturb the fragile traces. And the solution should bring as many nations as possible on board, from those likely to reach the moon to those who will share in the joy of seeing a citizen of the same Earth set foot on the moon again. After all, the plaque left by Armstrong and Aldrin reads: “We came in peace for all mankind.”