An astrophysicist from Queen's University Belfast is warning that Earth is incredibly vulnerable to an asteroid strike.
That scientist is Alan Fitzsimmons and he believes, "it is a case of when an asteroid collision will happen, rather than if it will happen."
"Astronomers find Near-Earth Asteroids every day and most are harmless. But it is still possible the next Tunguska would take us by surprise, and although we are much better at finding larger asteroids, that does us no good if we are not prepared to do something about them," said Fitzsimmons.
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A news release on the astrophysicist and his warning notes that Fitzsimmons "is highlighting the threat for Asteroid Day, a global event on 30 June. On that day in 1908, a small asteroid exploded over Tunguska in Siberia and devastated 800 square miles."
Professor Fitzsimmons is warning that a similar unexpected strike in today's world could easily destroy a major city and a larger asteroid could be more dangerous."