Closer than the moon, yet less well-mapped than Mars, the Earth’s seafloor is home to otherworldly creatures befitting a science fiction movie. Their remote habitat has caught the attention of humans, who are lining up to begin mining the bottom of the deep blue sea.

As technology and infrastructure drive the demand for minerals, and terrestrial resources grow harder to mine, the materials in the deep ocean are starting to look increasingly attractive to countries and companies.

“Deep-sea mining could end up having the largest footprint of any single human activity on the planet in terms of area of impact,” says University of Hawaii oceanographer Craig Smith.

It’s already underway: pioneer excavations in Papua New Guinea and Japan