Mjolnir, The Hammer of Thor
"Whosoever holds this hammer, if he be worthy, shall possess the power of... THOR"
Thor's principal weapon is the enchanted hammer named Mjolnir, one of the most formidable weapons known to man or god. Forged out of the mystical metal uru, whose chief properties are durability and ability to maintain enchantment, the hammer is two feet long and its handle is wrapped in leather which terminates in a thong. Besides being a nearly indestructible throwing weapon, the hammer has been given six enchantments by Odin to augment its physical qualities.
The first enchantment is that no living being can lift the hammer from the ground unless he or she is worthy. Hence, so far as is known, only Odin, Thor, and Beta Ray Bill are able to lift Mjolnir. Apparently no one without superhuman strength can lift the hammer, whether he or she is worthy or not.
The second enchantment causes the hammer to return to the exact spot from which it is thrown after striking its target.
The third enchantment enables the hammer's wielder to summon the elements of storm (wind, rain, thunder, lightning, and so forth) by stamping its handle twice upon the ground and willing it to do so. Thor can also project various forms of mystical energy from the hammer without striking it on the ground.
enables the hammer to open interdimensional portals, allowing its wielder to travel to other dimensions, such as Earth to Asgard. (It is not known how Thor locates the dimension to which he wishes to travel.)
The fifth enchantment, bestowed on the hammer by Odin in recent times, enabled Thor to transform into the mortal Don Blake, by stamping the hammer once upon the ground and willing the change to occur. When Thor became Blake, Mjolnir became a gnarled wooden cane. By stamping the cane upon the ground and willing the change to occur, Blake could turn himself back to his godly form of Thor, and the cane would again become the hammer. When the hammer was in the form of a cane, anyone could lift it. A provision of the enchantment required that the hammer could not be out of Thor's hand for over 60 seconds while he was on Earth without his spontaneous reversion to his mortal self.
Most of the fifth enchantment has been transferred to the hammer of Beta Ray Bill. However, enough of the fifth enchantment remains in Thor's hammer so that by stamping his hammer, he can instantaneously transform his Thor costume into Sigurd Jarlson's clothing, or vice versa. The hammer itself does not change form.
The hammer has had one enchantment that has been rescinded. Formerly the hammer could be swung in such a way as to generate chronal displacement inertia, enabling its wielder to travel through time. Most of this property, which is separate from the hammer's power to traverse dimensions, was removed by Immortus, and Thor himself recently apparently exhausted whatever time-traveling power Mjolnir had remaining.
By throwing the hammer and grasping its leather thong, Thor can magically propel himself through the air in the semblance of flight. Just as the hammer can magically change its course in order to return to his hand when he throws it, so can it be influenced by its wielder to change its course while it is in his grasp in flight. The precise manner in which Thor "steers" his hammer while in flight is not known, nor is the precise speed and distance Thor can attain with a single throw. Thor has been observed to be able to attain escape velocity from Earth's gravity with a single throw and to overtake space vessels.
