Power Cosmic

Power Cosmic is a powerful cosmic energy. It is what powers Galactus and his heralds, the Silver Surfer, Firelord, Terrax, and Nova. It grants them each incredible strength and durability. It allows them to travel through the harshness of space. They do not need to eat food or drink, though they do need to recharge with the power of a sun. They can also fire the energies in powerful blasts. When Silver Surfer betrayed Galactus, the planet eater allowed his former ally to keep the Power Cosmic so that all he encountered would know what he did.

The Phoenix Force has similar powers, though it has never been stated that the powers are the Power Cosmic.