Thor The Asgard
The Asgard are a group of benign aliens who were once a part of the Four Great Races. The Asgard are technologically advanced and are highly intelligent. They have helped protect humans on other planets from the Goa'uld, and on their protected planets, they are worshipped as Norse gods (from which all of their names are derived). When the humans are advanced enough to learn the truth- this level is determined through a series of tests- the Asgard reveal their true forms to them. Although advanced, the Asgard have a number of problems. Their galaxy has been attacked by the Replicators, intelligent, mechanical bugs that consume everything in their path. Because their attention has been focused on fighting the Replicators, the Asgard have had to resort to peace treaties with the Goa'uld, banking on the Goa'uld's fear of the Asgard's superior power. Furthermore, the Asgard are in danger of dying out. They currently 'reproduce' by transfering their consciousness into cloned bodies when the old ones die. The cloning procedure will soon no longer work because each successive body is weaker than the previous one. They believe that their answer lies in their ancestors, who once resembled current humans, so because of that, they also are very interested in the development of the human race.
Thor is the Supreme High Commander of the Asgard fleet. He has assumed the persona of the Norse god of thunder, Thor, and his original ship is the Bilskinir, which in Norse mythology is the name of Thor's hall. Thor has a great fondness for Jack O'Neill, beyond the simple admiration that all the Asgard have for Jack. (The Asgard regard O'Neill as a legend, and they even named their most advanced ship after him). Jack, in return, has affection for his "old buddy" Thor, and in "Small Victories," he actually invites Thor to go fishing. Thor protects the planet Cimmeria, on which he has installed Thor's Hammer, a device that transports any creature with a Goa'uld in it to a cavern. The cavern's exit is guarded by a forcefield that kills the Goa'uld, freeing the host. Of course, if any Jaffa are trapped in the cave, as Teal'c was in "Thor's Hammer," they would be killed. After SG-1 destroys the forcefield to free Teal'c, the Goa'uld invade Cimmeria in "Thor's Charriot." SG-1 must help the Cimmerians contact Thor by undergoing a series of tests; Thor, thinking that the Cimmerians are advanced enough to learn the truth about the Asgard, appears to them, but he is distraught when he realizes that the Cimmerians have received outside help. Nevertheless, he appears in the Bilskinir (Thor's "chariot") to deal with the Goa'uld and builds a new Hammer, which this time makes an exception for Teal'c. In Season 3's "Fair Game," Thor transports Jack O'Neill to his ship and tells him that because Earth has proved itself a danger to the Goa'uld, the System Lords plan on attacking Earth. The Asgard offer to include Earth in their Protected Planets Treaty with the Goa'uld, which would prevent any of the Goa'uld from attacking. The SGC agrees, and Thor presides over the negotiations as the Asgard representative. He offers O'Neill not-really-advice, as well, when negotiations take a turn for the worst. In "Nemesis," Thor's ship is attacked by the Replicators, and Thor is severely injured. The Replicators plan on invading Earth and consuming everything. Thor transports Jack to the ship in the hopes that Jack will discover a way to destroy it, and he apologizes to Jack for leading him to death. Sam and Teal'c board the ship, and Sam comes up with a plan to save them and Earth. Towards the end of the episode, Sam uses an Asgard medical chamber on Thor to prevent him from dying. His ship is destroyed as it descends towards Earth and crashes into the ocean, but not before SG-1 and Thor escape using the beamed-up Stargate. Season 4's "Small Victories" has Thor healthy once again, but he has grave news for the SGC: his homeworld is under attack by the Replicators. He needs their help- the humans have proved that their less-sophisticated weapons and thinking are effective against the Replicators, but the Asgard are no longer capable of thinking as humans do. Sam goes with him to save his planet. She eventually concocts out a wild plan, which succeeds even though Thor was at first reluctant to enact it. Afterwards, Sam gives Thor a big hug, which knocks his little head to the side. Sam apologizes, but Thor tells her that he is unharmed. When she tells him that their plan worked, he reminds her, in Asgard-humor fashion, that it was her "stupid idea." Season 5 finds Thor kidnapped by the Goa'uld Anubis, and his consciousness is downloaded into Anubis's ship. SG-1, sans the recently ascended Daniel, goes to save Thor against Thor's wishes, but after they rescue him, he falls into a coma. In Season 6's "Descent," the team eventually realizes that Thor's consciousness is still in the now-abandoned mothership. Thor had gained control of the ship; Anubis tried to destroy it by setting the self-destruct, but Thor stopped it. He then brought the vessel close to Earth, where SG-1 investigated it. Thor sent out a signal over the speakers, which, unencoded, was his own voice. He also rescued Sam and Jack from drowning by overwriting safety protocols in the ships computer. Sam and Davis realize what's going on; the team then rescues Thor's downloaded mind and send it to the Asgard. In later S6 episodes "Prometheus" and "Unnatural Selection," Thor, placed in a new body (which looks exactly like his old one), once again requests the assistance of SG-1 to help with the Replicator problem. In "Disclosure," Thor helps General Hammond and Major Davis cement an agreement with the ambassadors of China, Britian, and France regarding the secrecy of the Stargate program. He also manages to throw a few nicely aimed remarks at Senator Kinsey. In Season 7's "Fragile Balance," SG-1 discovers that Loki, a former Asgard scientist, has kidnapped Jack and replaced him with a malfunctioning clone. SG-1 contacts Thor. Thor chastises Loki, telling him that Jack has had his genetic code protected by the Asgard to prevent tampering. At the request of Jack, Thor then agrees to correct the mistake in the young Jack clone. Thor returns in the season premiere of Season 8, "New Order," on the Daniel Jackson, his new ship. He has been monitoring the Replicators (last seen in Season 6's "Unnatural Selection"). Because the Asgard needed a permanent solution to getting rid of the Replicators, Thor caused the planet's sun to collapse, creating a blackhole. Sam and Teal'c, who had been looking for the Asgard, are about to be pulled into the blackhole when Thor saves them. The Replicators unfortunately escape from the blackhole and head towards the new Asgard homeworld, so that they can feed off a certain metal necessary for the Replicators to create human-form versions of themselves. Thor and Teal'c return to Earth to pick up Daniel and Jack, in the hopes that Jack- who has the knowledge of the Ancients downloaded in his brain- will know a way to defeat the Replicators. Jack does, thankfully. Once the group accidentally figures out how to operate the new weapon- which releases an energy pulse that disables Replicators, causing them to fall apart into useless blocks- Thor configures the ship to emulate the effect. Thor then releases it over the Asgard colony, destroying all the Replicators, except for Fifth and his ship, which escaped. In "Covenant," Thor assists the SGC in covering up civilian plans to expose the Stargate program and the existence of aliens. He plays a small, but pivotal role in the episode, and he hangs out with Jack and the President of the US for a while.
Thor is played by alien Peter Avangelos. Here is his acceptance speech for Stargate SG-1 winning Best Canadian TV Series from the 2004 Spacey Awards:
Hello. My name is Peter Avangelos. I play Thor on the hit series Stargate SG-1. You know, for many years I have played this role. For many years I have sought glory and fame. For many years, it has eluded me. I am saddened by this. However, this award verifies that the fans have good taste... And of course, some of them taste good, too, if you know what I mean. Perhaps you don't. If you accept my invitation for a date, maybe you will know. Anyway, all seriousness aside, I would like to thank all the Canadian people who voted us for the second year in a row. Yes, that's two years in a row! This wonderful trophy. It is wonderful, as you can see. Very colorful, very unique... very sheek, as you know. I would like to thank Space, a wonderful, wonderful channel, so wonderful I can't stand it, you know. Most importantly, however, all seriousness aside again, I would like to thank the fans. The fans of science fiction in general, and especially the fans of space. Time, space... that burning senseation. All of those of you with hemorroids, you know what I mean. Is there any inner voice that would like to say something to me? (No. No.) Ah, my inner voices, they sound like tiny little farts. Thank you all for this award. Two years in a row. Two! Can you believe it? Can anyone believe it? (...) I have no more inner voices... I am so alone. In fact, I am so alone, you could call me Lonely.In Seasons 1 and 2, Thor was voiced by Mark Gibbon, but from Season 3 to the present, he has been voiced by Michael Shanks, who also plays Daniel Jackson. And on the Spacey Awards, "Peter Avangelos" was voiced by Richard Dean Anderson, and Thor was moved around by Amanda Tapping and Christopher Judge, who also played his inner voices.