The Deep Carbon Observatory (DCO), composed of 1,000 scientists from 52 countries, studies the underground ecosystems between Earth’s surface and its core. In a recent statement, this has been referred to as “Deep Biosphere” as a “subterranean Galapagos” potentially filled with millions of undiscovered species. Despite darkness and harsh conditions, life has been found as far as three miles below the continental subsurface and six-and-a-half miles below the ocean’s surface. The knowledge gained from these discoveries helps us understand the limits of life on Earth. Learn more at NBC.