Planetary geoarchaeology: New field of science will examine impact of humanity off Earth

In the midst of an escalating new space race, an intriguing scientific proposition has been put forward by a duo of Kansas Geological Survey researchers at the University of Kansas, alongside their colleagues. This team suggests a novel scientific sub-discipline, termed planetary geoarchaeology.

This emerging scientific field examines the impact of cultural and natural activities on other celestial bodies, such as Earth’s moon and Mars, and across the solar system. The focus lies in the processes that might be altering, preserving, or even destroying remnants of past and present space exploration.

Justin Holcomb is a postdoctoral researcher at the Kansas Geological Survey, as well as the lead author of the paper introducing this idea in the journal Geoarchaeology.

Why planetary geoarchaeology is important

Holcomb sheds light on the issue at hand. He states, “Until recently, we might consider the material left behind during the space race of the mid-20th century as relatively safe. However, the material record that currently exists on the moon is rapidly becoming at risk of being destroyed if proper attention isn’t paid during the new space era.”

Space exploration has seen humans dispatch more than 6,700 satellites and spacecraft into orbit. Not only from the U.S., these satellites hail from numerous countries worldwide.

The Union of Concerned Scientists details that the United States alone has over 4,500 satellites for civil, commercial, governmental, and military use. As the momentum picks up in space exploration and colonization, the preservation of space heritage becomes a pressing concern. Hence, the need for planetary geoarchaeology.

Holcomb adds, “We’re trying to draw attention to the preservation, study and documentation of space heritage because I do think there’s a risk to this heritage on the moon. The United States is trying to get boots on the moon again, and China is as well. We’ve already had at least four countries accidentally crash into the moon recently. There are a lot of accidental crashes and not a lot of protections right now.”

The genesis of planetary geoarchaeology

The idea of planetary geoarchaeology began to take form during the COVID-19 lockdown. It uses the techniques of geoarchaeology to extend the study of human migration to the wider reaches of space.

This approach aligns with the ODYSSEY Archaeological Research Program‘s focus. It is based at KGS and directed by Holcomb’s collaborator, Rolfe Mandel.

Mandel, a senior scientist at KGS and University Distinguished Professor in the Department of Anthropology, explains, “Human migration out of Africa may have occurred as early as 150,000 years ago, and space travel represents the latest stage of that journey. Although the ODYSSEY program is focused on documenting the earliest evidence of people in the Americas, the next frontier for similar research will be in space.”

The issue of determining what constitutes space heritage and what deserves preservation remains open to interpretation. Holcomb argues that all material currently on extraterrestrial surfaces is worthy of protection as it embodies our heritage. Planetary geoarchaeology would play a key role in this preservation.

Important landmarks such as the first footprints on the moon at Tranquility Base or the first Mars lander, Viking 1, carry immense historical significance. However, the sheer volume of material in orbit or on planetary surfaces presents a challenge.

Holcomb maintains, “We have to make those decisions all the time with archaeological sites today. The moon has such a limited record now that it’s totally possible to protect all of it. Certainly, we need to protect space heritage related to the Apollo missions, but other countries, too, deserve to have their records protected.”

Protecting humanity’s space heritage

With limited resources for safeguarding space heritage, Holcomb and his team advocate for the development of systems to track materials left in space.

Holcomb emphasizes the need for proactive measures. He says, “We should begin tracking our material record as it continues to expand, both to preserve the earliest record but also to keep a check on our impact on extraterrestrial environments.”

Moreover, Holcomb hopes to see the reach of planetary geoarchaeology extend beyond the moon. He would like it to also encompass matters relating to the exploration and migration to Mars.

The Spirit Rover, for example, became stuck in Martian sand in 2008. Moving sand dunes now pose a risk of entirely covering it.

“As planetary geoarchaeologists, we can predict when the rover will be buried, talk about what will happen when it’s buried and make sure it’s well documented before it’s lost,” he explained.

Holcomb believes that future NASA missions should include geoarchaeologists to ensure the protection of space heritage. Holcomb, personally, would prefer to stay earthbound. However, he still envisions the necessity for archaeologists to be part of space exploration.

Holcomb concludes, “I’ll leave that to other geoarchaeologists. There’s plenty to do down here, but I do hope to see an archaeologist in space before it’s all over.”

More about geoarchaeology

Geoarchaeology is an interdisciplinary field of study that applies the concepts and methods of geosciences to archaeological research. Its focus is on understanding the relationship between humans and their natural environment throughout history.

This includes the study of the impact of human activities on landscapes. It also examines how natural environmental changes have influenced human behavior and societies. In addition, it includes the new sub-field we discussed above, planetary geoarchaeology.

Here are some key aspects of geoarchaeology:

Soil and sediment analysis

Geoarchaeologists often study soils and sediments in and around archaeological sites. By understanding their formation and distribution, they can determine the environmental conditions at the time the site was inhabited. From there, they can understand how the site was used by humans.

Site formation processes

Geoarchaeologists examine the formation and modification of archaeological sites over time. This involves examining how human activities and natural processes such as erosion and deposition have influenced the accumulation and preservation of artifacts and other archaeological materials.

Landscape archaeology

This branch of geoarchaeology investigates how ancient peoples influenced and were shaped by their surrounding landscape. It can involve mapping and analyzing features like ancient fields, irrigation systems, or settlements.

Paleoenvironmental reconstruction

Using techniques like pollen analysis, dendrochronology (tree-ring dating), and isotopic analysis, geoarchaeologists can reconstruct past climates and environments. This helps to understand how changes in climate and environment may have impacted ancient societies.

Dating techniques

Geoarchaeologists often use dating methods such as radiocarbon dating, thermoluminescence, and optically stimulated luminescence to determine the age of artifacts, structures, or sediment layers.

Remote sensing and geophysical techniques

Technologies like ground-penetrating radar, aerial photography, and satellite imagery can help identify archaeological sites or understand large-scale landscape features. These techniques can provide valuable information while minimizing the disruption of the site through excavation.

Micromorphology

This involves the microscopic analysis of soils and sediments to identify human activities or natural processes at an archaeological site.

In summary, geoarchaeology provides archaeologists with a set of powerful tools to understand the context and history of archaeological sites. It forms a bridge between the human and natural sciences, providing valuable insights into the complex relationships between human societies and their environments over time. Planetary geoarchaeology will be a welcome sub-field to this important branch of science.