The movie has been filming since July, but few details have emerged.
It looks like Hemsworth has taken the lead on sharing moments from the set, such as the first look at himself and Thompson in costume.
Simply called MIB, the film is technically a spin-off because it will not see the return of former series leads Will Smith and Tommy Lee Jones.
Instead, Chris Hemsworth and Tessa Thompson are stepping up as Agents H and M, who will no doubt have to prevent some sort of alien catastrophe from destroying the planet.