Martian artifacts: trash or treasure?

Experts are calling for the preservation of human “heritage” on Mars, which they trace back to the crash landing of a Soviet rover in 1971.

University of Kansas anthropologist Justin Holcomb advocates for tracking and preserving human artifacts on Mars, arguing that so-called "space trash" is, in fact, a valuable archaeological resource.

In a new peer-reviewed paper published in Nature Astronomy, Holcomb and a group of other anthropologists make a case for cataloging physical objects related to human Martian exploration as a way of chronicling humanity’s first interplanetary exploration attempts.

“Our main argument is that Homo sapiens are currently undergoing a dispersal, which first started out of Africa, reached other continents and has now begun in off-world environments,” Holcomb says.

He sees human spacecraft, landers, rovers, and other space debris “littering” Mars as modern-day equivalents of Clovis points, distinctive stone tools representing one of North America's earliest well-documented human cultures.

“These artifacts are very much like hand axes in East Africa or Clovis points in America. They represent the first presence, and from an archaeological perspective, they are key points in our historical timeline of migration,” Holcomb says.

Just as "middens" – ancient garbage dumps – reveal secrets of past societies on Earth, debris often dismissed as space trash represents the first material record of modern humanity’s presence on another planet.

According to Holcomb, it is critical to shift the narrative because the “solution to trash is removal, but the solution to heritage is preservation.” This distinction is important, he explains, to ensure that future missions consider these objects when planning landing sites.

Space archeology

In his earlier work, Holcomb argued for a declaration of a “lunar anthropocene,” or age of human dominion over the moon’s landscape.

“On Mars, we don't think there's an anthropocene, but there is an archaeological record that needs to be a stratigraphic horizon, allowing us to place this material into a framework. And of course, we could do this across the solar system,” he says.

According to the researcher, human impact on the Martian landscape can be traced to the crash landing of the Soviet Union’s Mars 2 rover in 1971. It is the first time human species left a “preserved” imprint on the surface of another planet.

Human artifacts in otherworldly environments will be affected differently, something that should be taken into account when working on their preservation.

“Planetary geoarchaeology is a future field for sure, and we need to consider the materials not only on Mars in general but also in various places on Mars, which have different processes,” Holcomb says.

Some environmental aspects to consider include the planet’s ice-covered polar regions, its iron-rich sands, and global dust storms that are unique to Mars.

“The Spirit Rover, for example, is right next to an encroaching dune field that will eventually bury it. Once it's buried, it becomes very difficult to relocate,” Holcomb says, referring to NASA’s Mars rover that was active between 2004 and 2010.

Experts propose cataloging human-made materials on Mars and other planets humans may visit, using either new databases or existing ones, such as the UN Register of Objects Launched into Outer Space.

Earlier this year, a crew aboard the International Space Station (ISS) carried out what was described as the “first-ever” archeological survey in space.

Astronauts were asked by a team of archaeologists to take daily pictures of six locations around the station for 60 days between January and March in 2022 as part of the ISS Archeological Project.

Led by Justin Walsh of Chapman University, California, researchers then analyzed the thousands of photos using archaeological techniques.