Asteroids?

Depends on the size and how many. I can't say for sure if it will be end of all humanity, but why worry about it.

format_quote Originally Posted by Skillganon

Depends on the size and how many. I can't say for sure if it will be end of all humanity, but why worry about it.

It's not that I'm worried, but if u think of it we basicly can't defend against one, it's a bit like global warming no one will take it seriously till were all swimming to work

The impact of a major asteroid hitting us would just be the begining of the problem. the immediate devastation would just be on a local level probably only a few hundred square miles.

The problem will be the huge amount of dust put into the atmosphere. We know that from just the one volcano of Krakatoa that suffieient dust was lifted to effectilvy reduce sunlight for 3 years. The first year was known as the year without a summer. There were no summer temperatures anywhere on earth the first year. It even snowed in the USA in July. the dust caused reduced temperatures for at least 3 years.

A large asteroid would change the climate for at least hundreds of years. It is these climatic changes that would alter the Earth. Reduced food production etc.

What would happen would depend on how big it was. Small asteroids hit us all the time, the larger ones of which produce about as much energy as a Hiroshima bomb. Medium-sized asteroids cause huge explosions and leave big craters, like the famous one in America. An impact would mean that a large area of land would be devastated, and huge famines would follow. Fortunately for us, these impacts are much less common. The largest impacts are much worse than this, and could easily put an end to humanity. No matter where it hit, it would cause huge fires all over the world, months of darkness, and the climate would go into a short ice age. Fortunately these only happen about every 100 million years, and the most recent was about 65 million years ago, when the dinosaurs died out.
However, in the early 20th century, what is now believed to be a comet exploded over Siberia, levelling forests and blowing people off their feet. There was no crater, because it exploded in the air instead of hitting the ground, but if it did hit we would probably still be having problems because of it now.