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How Big Does An Asteroid Need To Be To Wipe Out Life On Earth?
Examining hazardous asteroid sizes
One of the most popular clickbait headlines involves nearby asteroids and meteoroids. These articles trumpet that large space rocks are due to pass near the Earth, leaving people wondering about the chances of an impact. More often than not, these rocks are usually very small and are traveling in an orbit that takes them beyond the orbit of the moon. The presence of dark space rocks flying near the Earth is concerning, but most of these rocks are relatively harmless. It raises the question, how big does an asteroid need to be to threaten humanity’s survival?
The answer is a lot bigger than you think.
A City Killer (200ft)
It does not take much for an asteroid to destroy a large city. Astronomers estimate that it would only take a dense asteroid measuring 200ft on a side to flatten some of the largest cities in the world. An asteroid measuring 200ft would release as much energy as mankind’s most powerful nuclear warheads. The result would be a five mile radius of complete destruction and an airblast that would radiate outwards and rattle buildings for miles around. If an asteroid this size hit the heart of a major city, the city would likely be destroyed.
