Journey Into Mystery #83 (1962)

Part 1: The Mighty Thor and the Stone Men from Saturn! Donald Blake, a doctor from the United States, is visiting Norway. At the same time, a ship from Saturn lands nearby as advance scouts for a planned invasion. A local fisherman spots them and alerts the villagers, but they dismiss him. Blake overhears and goes to look for himself. When he steps on a twig, the aliens notice him. He flees into the hills, where he loses his cane. He runs into a cave, but the other entrance is blocked by a giant boulder. A secret door opens, revealing a chamber where Blake finds a walking stick. He tries to move the boulder with the stick but is unable to get leverage. Frustrated, he hits the boulder with the stick, and, in a flash of light, the stick transforms into a hammer, transforming Blake into Thor, the mythical Norse God of Thunder. Part 2: The Power of Thor! Thor easily lifts the boulder and leaves the cave. He verifies that the hammer has all the powers of Mjolnir, Thor's legendary weapon. He discovers it gives him the power to create storms and that the hammer is indestructible and will come back to him if thrown. Meanwhile, the alien armada shows up on Earth's radar screens. When fighter jets scramble to meet them, they project an image of a huge dragon and frighten away the pilots. When the ground forces fire missiles, they explode harmlessly against the ships' force fields. Thor speeds to the defense of the Earth. Part 3: The Mighty Thor Strikes Back! When Thor attacks the aliens, they drop a cage over him, but he tears the bars open. They aim their disintegration beams at him, but his hammer smashes their guns. They unleash their Mechano-Monster, but he smashes it to bits. The aliens return to their ships and give up their invasion. Thor changes back to Dr. Blake, whom the soldiers ignore when they come to look for the invaders.