CaptainWacky
I want to smell dark matter
AS in "like gangbusters!"?
The original sense of gangbuster was the disappointingly obvious 'one who busts gangs', specifically, 'a law-enforcement official who is actively engaged in breaking up criminal gangs'.
This word was popularized as Gang Busters, the title of an extremely popular CBS radio series that premiered on January 15, 1936, and was broadcast until 1957. This series began with a stretch of explosive sound effects, featuring machine guns, police sirens, and the like.
In reference to these violent sound effects, the expression like gangbusters appeared by 1940 in the sense 'aggressively; forcefully; energetically'; and hence as a more general intensive 'excitingly; well'. The expression was especially popular among jazz musicians, often in the phrase come on like gangbusters. This remains the most common use of the term: "Perception is almost everything in these stocks--if people perceive that a company is back on track, all of a sudden a wallflower comes back like gangbusters" (Fortune, 1996).
Gangbusters has been used as an adverb since the 1970s, usually in the phrase go gangbusters 'to be extremely successful or vigorous', but sometimes in examples like your "raining gangbusters." Finally, since the 1980s we've started to see gangbusters as an adjective meaning 'vigorous; successful; exciting': "Smith's gangbusters novel...has become...[an] expertly modulated thriller" (Entertainment Weekly, 1998 ).