A group of scientists are proposing that the inhabitants of Earth build a “lunar ark” as a global insurance policy against total annihilation. The idea, reminiscent of a backup hard drive to reboot a dead Earth, is to create a vault on the surface of the moon that would store the cryogenically frozen genetic material of our planet’s 6.7 million species of plants, animals and fungi, reports Harry Baker for Live Science.
"Earth is naturally a volatile environment," says Jekan Thanga, an aerospace researcher at the University of Arizona and one of the concept’s chief architects, in a statement. "As humans, we had a close call about 75,000 years ago with the Toba supervolcanic eruption, which caused a 1,000-year cooling period and, according to some, aligns with an estimated drop in human diversity."
Thanga also points out that existing banks of genetic material, such as the Svalbard seed vault in Norway, are being threatened by climate change-driven sea level rise. Other existential threats include global nuclear war, asteroid impact, pandemic, global solar storm and global drought. Thanga says this underscores the importance of safeguarding biodiversity by creating a genetic ark on another celestial body.
The proposal, presented last week during the IEEE Aerospace Conference, suggests the lunar ark be constructed inside one of the moon’s many hollow lava tubes. Placing the ark inside one of these more than 300-foot diameter tubes, the researchers say, would shield the ark and its sensitive contents from solar radiation, meteorites and temperature changes.
"What we envision is taking one of the existing pits—just the opening into the lava tube—and installing an elevator shaft there," Thanga tells Courtney Linder of Popular Mechanics. The elevator would be the facility’s entry and exit, with the library-like cryogenic preservation modules below storing samples at negative 292 degrees Fahrenheit in the case of seeds and at minus 320 degrees for stem cells. Fortunately, the lunar lava tubes already hover at a chilly minus 15 degrees.
Getting all the genetic material—totaling 335 million individual samples—to the moon would require some 250 rocket launches. That’s more than six times the number of launches that were required for the construction of the International Space Station, reports Sophie Lewis for CBS News.
These estimates are quick and dirty “back of the envelope calculations,” Thanga tells Live Science. The calculations assume each species would require 50 samples to be successfully reintroduced. But in reality, it could take as many as 500 samples to provide enough genetic diversity to a species starting from scratch, meaning even more rockets. The 250-rocket estimate also doesn’t include the to-and-fro necessary to build the lunar ark in the first place.
Even so, Thanga tells Popular Mechanics that making the lunar ark a reality might be possible in the next 30 years, especially in light of the strides private companies such as SpaceX have made recently in bringing down the cost of space travel.
"It will cost hundreds of billions of dollars to build the ark and transport samples," Thanga tells Live Science. "But this isn't totally out of the question for international collaborations like the U.N."