The Devils Comet

Pons and Brooks may have discovered me  
But I've existed since the beginning of history  
Travelling around haunting the universe  
Altering space and time with my death curse  
Tempting your mind with harbingers of change  
Causing public unrest to be so deranged  
Some just see my glowing head and tail  
But others know my true message details  
I'm not just frozen chunks of dust rock and ice  
I have an unstable diatomic composition inside    
When my nucleus explodes you will feel my horns  
No longer can you hide under your rose of thorns  
Attacking you with epidemics and seismic events    
Causing your hearts and thoughts to descent  
I effect everyone and everything in my path  
And every 71 years you will feel my wrath