With Earth’s biodiversity increasingly threatened and at risk, scientists have intensified research into establishing and maintaining a long-term backup of life. In the journal *BioScience, a team of researchers, led by Dr Mary Hagedorn from the Smithsonian’s National Zoo and Conservation Biology Institute, propose a storage facility based on the Moon with frozen samples of genetic material from the most endangered species. They believe that the Moon’s unique environment could be the perfect solution to the biodiversity crisis, providing a place where, if need be, species could be partially ‘resurrected’ using genetic engineering.The proposal is for a passive lunar biorepository for long-term storage of prioritised taxa of live cryopreserved samples to safeguard Earth’s biodiversity and to support future space exploration and planet terraforming. The initial focus will be on cryopreserving animal skin samples with fibroblast cells. An exemplar system has been developed using cryopreserved fish fins from the Starry Goby, Asterropteryx semipunctata. Samples will be expanded into fibroblast cells, recryopreserved, and then tested in an Earth-based laboratory for robust packaging and sensitivity to radiation. Two key factors for this biorepository are the needs to reduce damage from radiation and to maintain the samples near minus 196 degree Celsius. Certain lunar sites near the poles may meet these criteria. If possible, further testing would occur on the International Space Station prior to storage on the Moon.The proposal merits attention since even under the most optimistic models of global climate change, a staggering proportion of Earth’s biota will go extinct. Because of myriad anthropogenic drivers, a high proportion of species and ecosystems face destabilisation and extinction threats that are accelerating faster than our ability to save these species in their natural environment. Hence the urgent need to envision innovative strategies to conserve Earth’s biodiversity to protect ecosystems of the future.Through cryopreservation cells can remain frozen but alive for hundreds of years. With increasing success, collections of cryopreserved materials can be thawed to recover DNA, intact cells, and even whole functional organisms. Many institutions globally maintain cryopreserved biological collections, especially those concerned with human health, but fewer biorepositories hold live wildlife samples in a frozen state. But, all these biorepositories require intensive human management, electrical power, and an ongoing supply of liquid nitrogen, which makes them susceptible to unpredictable natural and geopolitical disasters. Today, many frozen collections are stored in urban centres, making them even more susceptible to destabilisation threatsIn 4.5% of the Moon’s southern pole, seasonal temperature variation is stable year-round at or below minus 196 degree Celsius, to suspend all biological activity. Such a biorepository would safeguard biodiversity and act as a hedge against its loss occurring because of natural disasters, climate change, overpopulation, resource depletion, wars, socioeconomic threats, and other causes on Earth. Initially, this would be a vault for live, cryopreserved samples of the most at-risk animals on Earth to safeguard our biodiversity and to support future space exploration, as well as planet terraforming taxa, with other organisms and plants to be added in the future.The goal is to cryopreserve most animal species on Earth. In addition to safeguarding Earth’s biodiversity, a lunar biorepository would advance our fundamental understanding of how cells behave in space and would also preserve animal, plant, and microbial samples that may be essential to human exploration of the solar system or galaxy. The biorepository could store biomaterials for food, filtration, microbial breakdown, and ecosystems engineering.The Arctic Svalbard Global Seed Vault, in Norway, is a passive biorepository that maintains seeds at minus 18 degree Celsius because of the natural surrounding temperature of the permafrost. While changing climatic conditions threaten the stability of the Svalbard Seed Vault, on the Moon there is no atmosphere and, therefore, no threat of climate change. Human activity on the Moon in the decades to come may increase dramatically and establishing and maintaining a long-term backup of life from Earth is of critical scientific value. Ideally an international agreement on a shared lunar biorepository would provide an effective long-term solution to protect life.