Scientists devise method to secure Earth's biodiversity on the moon

The paper, published today in BioScience and written in collaboration with researchers from the Smithsonian's National Zoo and Conservation Biology Institute (NZCBI), Smithsonian's National Museum of Natural History, Smithsonian's National Air and Space Museum and others, outlines a roadmap to create a lunar biorepository, including ideas for governance, the types of biological material to be stored and a plan for experiments to understand and address challenges such as radiation and microgravity. The study also demonstrates the successful cryopreservation of skin samples from a fish, which are now stored at the National Museum of Natural History.

"Initially, a lunar biorepository would target the most at-risk species on Earth today, but our ultimate goal would be to cryopreserve most species on Earth," said Mary Hagedorn, a research cryobiologist at NZCBI and lead author of the paper. "We hope that by sharing our vision, our group can find additional partners to expand the conversation, discuss threats and opportunities and conduct the necessary research and testing to make this biorepository a reality."

The proposal takes inspiration from the Global Seed Vault in Svalbard, Norway, which contains more than 1 million frozen seed varieties and functions as a backup for the world's crop biodiversity in case of global disaster. By virtue of its location in the Arctic nearly 400 feet underground, the vault was intended to be capable of keeping its seed collection frozen without electricity. However, in 2017, thawing permafrost threatened the collection with a flood of meltwater. The seed vault has since been waterproofed, but the incident showed that even an Arctic, subterranean bunker could be vulnerable to climate change.

Unlike seeds, animal cells require much lower storage temperatures for preservation (-320 degrees Fahrenheit or -196 degrees Celsius). On Earth, cryopreservation of animal cells requires a supply of liquid nitrogen, electricity and human staff. Each of these three elements are potentially vulnerable to disruptions that could destroy an entire collection, Hagedorn said.

To reduce these vulnerabilities, scientists needed a way to passively maintain cryopreservation storage temperatures. Since such cold temperatures do not naturally exist on Earth, Hagedorn and her co-authors looked to the moon.

The moon's polar regions feature numerous craters that never receive sunlight due to their orientation and depth. These so-called permanently shadowed regions can be −410 degrees Fahrenheit (−246 degrees Celsius) -- more than cold enough for passive cryopreservation storage. To block out the DNA-damaging radiation present in space, samples could be stored underground or inside a structure with thick walls made of moon rocks.

At the Hawai?i Institute of Marine Biology, the research team cryopreserved skin samples from a reef fish called the starry goby. The fins contain a type of skin cell called fibroblasts, the primary material to be stored in the National Museum of Natural History's biorepository. When it comes to cryopreservation, fibroblasts have several advantages over other types of commonly cryopreserved cells such as sperm, eggs and embryos. Science cannot yet reliably preserve the sperm, eggs and embryos of most wildlife species. However, for many species, fibroblasts can be cryopreserved easily. In addition, fibroblasts can be collected from an animal's skin, which is simpler than harvesting eggs or sperm. For species that do not have skin per se, such as invertebrates, Hagedorn said the team may use a diversity of types of samples depending on the species, including larvae and other reproductive materials.

The next steps are to begin a series of radiation exposure tests for the cryopreserved fibroblasts on Earth to help design packaging that could safely deliver samples to the moon. The team is actively seeking partners and support to conduct additional experiments on Earth and aboard the International Space Station. Such experiments would provide robust testing for the prototype packaging's ability to withstand the radiation and microgravity associated with space travel and storage on the moon.

If their idea becomes a reality, the researchers envision the lunar biorepository as a public entity to include public and private funders, scientific partners, countries and public representatives with mechanisms for cooperative governance akin to the Svalbard Global Seed Bank.

"We aren't saying what if the Earth fails -- if the Earth is biologically destroyed this biorepository won't matter," Hagedorn said. "This is meant to help offset natural disasters and, potentially, to augment space travel. Life is precious and, as far as we know, rare in the universe. This biorepository provides another, parallel approach to conserving Earth's precious biodiversity."

The study was co-authored by Hagedorn and Pierre Comizzoli of NZCBI, Lynne Parenti of the National Museum of Natural History and Robert Craddock of the National Air and Space Museum. Collaborators from other institutions include Paula Mabee of the U.S. National Science Foundation's National Ecological Observatory Network (Battelle); Bonnie Meinke of the University Corporation for Atmospheric Research; Susan Wolf and John Bischof of the University of Minnesota; and Rebecca Sandlin, Shannon Tessier and Mehmet Toner of Harvard Medical School.