Engineers want to build an underground lunar ark, filled with millions of seed, spore, sperm and egg samples from Earth’s species, hidden in a network of tubes on the moon to provide a genetic backup for the planet in the event of a doomsday scenario.Engineers want to build an underground lunar ark, filled with millions of seed, spore, sperm and egg samples from Earth’s species, hidden in a network of tubes on the moon to provide a genetic backup for the planet in the event of a doomsday scenario.