Discovery of Naturally Occurring Single-Walled Carbon Nanotubes and Graphitic Carbon on the Far Side of the Moon.

Abstract

Multidisciplinary efforts to catalogue the existence of elements and their material forms remain ongoing, particularly for carbon, which is abundant in several forms, such as graphene, carbon nanotubes (CNTs), and diamond. This study presents the first identification of graphitic carbon in lunar samples taken by Chang'E-6 (CE-6) mission from the far side of the Moon, which was observed through multiple spectroscopy and microscopy techniques at identical locations. Although CNTs have been predominantly assumed to require artificial preparation, the study findings demonstrate that these materials exist in nature. Specifically, single-walled CNTs were identified in the CE-6 lunar samples, which were formed through micrometeorite impacts and an Fe-driven catalysis process under early volcanic activities and solar wind irradiation on the lunar surface. These findings, together with previously reported natural few-layered graphene on the Moon's near side, may inspire a paradigm shift in carbon science and offer new pathways for designing Human-fabricated novel and emerging materials.