Astronium is a Pink/Green color resource found towards the core of Terran, Barren, and Exotic (Found on surface of Radiated Planet). It is shaped like compound (See Compound) and can only be mined by a drill on the truck or rover. It has no known use at the moment, but it is believed that it will be a power source in later updates.

WARNING: It may take up to three hours to get to the core of a planet, and gravity starts to lower the closer you get to the core.