A proposed lunar biostorage could allow genetic samples to be stored without the need for electricity or liquid nitrogen. A new study led by scientists at the Smithsonian Institution proposes a plan to protect Earth’s endangered biodiversity by cryogenically preserving biological material on the Moon. The moon’s permanent shadow craters are cold enough for cryogenic storage without the need for electricity or liquid nitrogen, the researchers say.

The paper, published in BioScience and written in collaboration with the Smithsonian National Zoo and Conservation Biology Institute (NZCBI), the Smithsonian National Museum of Natural History, the Smithsonian National Air and Space Museum, and other researchers, outlines a roadmap for creating a lunar biorepository, including management ideas, types of biological material to be stored, and a plan of experiments to understand and solve problems such as radiation and microgravity. The study also reveals the successful cryopreservation of fish skin samples currently housed at the National Museum of Natural History.

Vision and inspiration

“Lunar biorepository will initially target the most at-risk species on Earth today, but our ultimate goal will be to cryopreserve most species on Earth,” said Mary Hagedorn, a 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 research and testing needed to make this biorepository a reality.”

The proposal is inspired by the Global Seed Vault in Svalbard, Norway, which contains more than 1 million frozen seed varieties and acts as a backup for the world’s crop biodiversity in the event of a global disaster. The vault was designed to store the seed collection frozen without electricity, due to its location in the Arctic, some 400 meters below ground. However, in 2017, the melting of the permafrost threatened the collection with meltwater flooding. The seed vault has since been sealed, but the incident showed that even an underground shelter in the Arctic can be vulnerable to climate change.

Unlike seeds, animal cells require much lower storage temperatures for preservation (-320 degrees Fahrenheit, or -196 degrees Celsius). Cryopreserving animal cells on Earth requires liquid nitrogen, electricity and human personnel. Each of these three elements is potentially vulnerable to failure that could destroy an entire collection, Hagedorn said.

To reduce this vulnerability, scientists needed a way to passively maintain the temperature of cryopreservation storage. Since temperatures this low don’t exist on Earth, Hagedorn and his co-authors looked to the Moon.

The Moon’s polar regions contain numerous craters that, due to their orientation and depth, never reach sunlight. These permanently shadowed regions can have temperatures as low as -410 degrees Fahrenheit (-246 degrees Celsius), more than enough for passive cryopreservation. To block DNA-damaging radiation in space, samples can be stored underground or inside thick-walled structures made of moon rock.

Current research and future directions

A team of researchers at the Hawaii Institute of Marine Biology has cryopreserved skin samples from a reef fish called a star goby. The swimmers contain a type of skin cell called fibroblasts, which are the primary material for storage in the National Museum of Natural History’s biorepository. When it comes to cryopreservation, fibroblasts have several advantages over other types of cells commonly cryopreserved, such as sperm, eggs and embryos. Science has yet to reliably preserve sperm, eggs and embryos from most wildlife species. But for many species, fibroblasts can be easily cryopreserved. Fibroblasts can also be collected from animal skin, which is easier to collect than eggs or sperm. For species without skin, such as invertebrates, Hagedorn said the team could use a variety of sample types, including larvae and other reproductive material, depending on the species.

The next steps will be to begin a series of radiation exposure tests on fibroblasts cryopreserved on Earth to help develop a package that can safely send samples to the Moon. The team is actively seeking partners and support to conduct additional experiments on Earth and the International Space Station. Such experiments will provide a reliable test of the prototype package’s ability to withstand the radiation and microgravity associated with space travel and lunar storage.

If their idea becomes reality, the researchers envision the lunar biorepository as a public enterprise that would include public and private sponsors, scientific partners, countries and members of the public, with shared governance mechanisms similar to the Svalbard Global Seed Bank.

“If Earth fails, if Earth is biologically destroyed, we’re not saying this biorepository will be irrelevant,” Hagedorn said. “Its purpose is to stabilize natural disasters and potentially increase space travel. Life is precious and, as we know it, rare in the universe. This biorepository provides a different and parallel approach to preserving Earth’s precious biodiversity.”