The Tunguska Event
One morning in Siberia (June 30th, 1908) something unknown caused massive destruction when it streaked across the early sky. Investigations were not set up until 1921. They found that the total area of damage spanned about 800 square miles. When further investigation was done, nothing was found in the center of debris besides a tree stump. Finally, in 1978 (70 years later!) astronomer Lubor Kresak realized that the Tunguska event occurred at the height of a Beta Taurid meteor shower. He believed that the destruction was caused by Comet Encke. Today, scientists believe it to be a asteroid comet hybrid (possibly). What I found most amazing about this entire thing was that it took decades to actually even begin to thoroughly investigate what happened.