Why is comet considered bad omen?

Comets are considered an omen of misfortune, due to its appearance coinciding with disasters and epidemics.

Comets are considered bad points because throughout the history of comets there is an unpredictable cycle. And by chance, it always appears at times of disaster or disaster.

Halley comet.

In England, Halley comet has been thought to bring "" in Europe which is considered the worst natural tragedy in human history.

Or comets have appeared on the day of assassination and died.

Next, because of the comet instability cycle, it is possible to stab and destroy the Earth.

Many scientists believe that 13,000 years ago comets have crashed into Earth, causing many large species to become extinct and the climate is changed for 1300 years. This hypothesis is based on the carvings in Turkey.

Scientists also predicted that in 4479 there would be a 26km-wide comet that could destroy the Earth. However, it is still an interesting case for astronomers to study.