Supposedly the sterilization bombing lasted "thirty-three standard hours".Ipyr
In Paul of Dune, Ipyr is the homeworld of Earl Memnon Thorvald, a noblemen who leads the resistance against the rule of Paul "Muad'Dib" Atreides after the events of Dune.[16] When Paul discovers Thorvald's intent to devastate the Atreides planet of Caladan, he forces the Spacing Guild to eject Thorvald and his followers into deep space and leave them to die.[16] Paul's forces then "sterilize" Ipyr, using "weapons, explosives, highly toxic chemical bombs, defoliants, and wide-dispersal incendiaries" to destroy every living thing and render the planet uninhabitable.[16]
Footnote 16: Herbert, Brian; Kevin J. Anderson (2007). Paul of Dune, pg. 468-469.
I think we've pointed this out before, but why waste all those munitions Why not, instead, just spend that time towing a sufficiently large asteroid into a collision course and letting it do all the work? Then use bombs and whatever to wipe out any survivors.
I guess that wouldn't seem brave enough or active enough? Not enough weapons special effects potential in the movie version?
It's just stupid and pointless....
(On the talk page, I left TAnthony this note:
)Forgot something in the list of weapons used on the planet:
As yet unsold copies of Hunters and Sandworms were dropped on many cities before the employ of more conventional bombs.