We don't think we've ever seen Sheldon Cooper, played by Jim Parsons (45), this excited ever! In the 12th and final season of the The Big Bang Theory one of Sheldon's biggest idols will be visiting Leonard and Sheldon at home. William Shatner (87), who played Captain Kirk in the original Star Trek series, will be going down in The Big Bang Theory history.

The Big Bang Theory meets Star Trek

In The Big Bang Theory episode The D & D Vortex Wil Wheaton (46) organises a Dungeons and Dragons tournament, in which not only William Shatner, but also other stars such as Kevin Smith (48) and Joe Manganiello (42), take part. Two trailers for what looks set to be a truly legendary episode have been released so far. 

William Shatner is one of Sheldon's greatest idols, which is why the physicist is totally flabbergasted when his favourite actor of all time appears in front of him. Sheldon happily welcomes him, shouting "Captain on the bridge, Captain on the bridge" and immediately asks him if he can address him as Captain Kirk

Numerous celebs have had guest appearances on The Big Bang Theory, including several Star Trek actors such as George Takei (81) and Leonard Nemoy (†83). Wil Wheaton, who stars as Wesley Crusher in The Next Generation, has even become a main cast member. 

William Shatner's upcoming The Big Bang Theory appearance looks to be a particularly special one and it is not only Sheldon's emotions that will be running high!