The phenomenon has been around forever. Ancient people liked to put 'blood' in front of things (we just had a Blood Moon) and august personages such as Homer made note of it.
You wouldn't think dust could travel 2,000 miles - over an ocean - but it can.
Storms in the Sahara desert create a fine dust that can eventually mix with rain. When this new mixture eventually falls, it can have a reddish color and then it leaves a layer of dust on that car you just washed. The science reason, according to a study in Phylogenetics and Evolutionary Biology, is the presence of spores of the green microalgae Trentepohlia annulata.
Link
When it hits in areas with more pollution it can mean an even bigger mess. Sometimes it can topple kingdoms. As Sarah Knapton in The Telepraph notes, The Anglo Saxon Chronicle recorded that in 685, "there was a bloody rain in Britain. And milk and butter were turned to blood. And Lothere, king of Kent, died".
Coincidence? Sure, if you say so. But I am betting Camilla is not a Queen (or royal consort, or whatever) by Sunday.
