So I recently bought the To wake the Mangog tpb which collects Thor 154-174 and in issue 161 we find the first appearance of Ego the living planet who battles with Galactus while Thor is journeying there to try and destroy Galactus. Mayhem ensues and Thor ends up on Ego while Galactus is preparing to destroy him and everyone else on the planet who who had landed there. This leads to the following scan

Which I believe is the first use of the godblast and which would have killed Galactus had he not fled from it. Just thought I would post it since its a pretty amazing feat that I had never seen posted before.

Yeah Stan and Jack wrote Thor to be Marvel's version of a Superman without being a Superman clone in terms of origins and powers (a la Hyperion, Gladiator, etc.). Stan wanted to create someone "more powerful than the most powerful man" so he used a Norse god as the model and brought Thor to the Marvel universe. Similar to Superman Thor had a human alter-ego Donald Blake and as a contrast, Thor as Blake was a handicapped physician. It's why Thor from his inception probably up until the end of Jurgens' run was performing uber-powerful feats much more frequently than his post-2007 return.

@haveatthee: ya, I think most Thor fans know he was basically Marvel's answer to Superman back then but this is still the strongest feat I can ever recall him doing. Nearly one shotting Galactus and no one can really say its pis since it was one of Galactus' first appearances and it being written by Stan and Jack which shows you how powerful they originally intended Thor to be. Odin is also seen as an equal to Galactus imo and even sends Thor on a mission to destroy Galactus after this incident or to bring him before Odin for judgement. Though what ends up happening is Galactus tells Thor his origin story and Odin tells Thor that he can come home.