"Worlds in Collision" is the title of a book by Immanuel Velikovsky in which he proposes, that some of the Exodus plagues were caused by successive close approaches to Earth by the planet Venus.
September 17th
Wormwood
Gall is an example of something which can be used to express either cause or effect. Bible passages that refer to the water of gall sometimes connect the concept to something called wormwood.
November 6th
The third trumpet is the third plague which involves large quantities of material falling out of the sky. The stars fall from heaven as the continents are moved into a contiguous landmass.