* August 11, 1999: Total solar eclipse visible across Europe, the Middle East, and parts of Asia. This was a highly anticipated event, with many people traveling to see the eclipse.

* August 16, 1999: Peak of the Perseid meteor shower. This annual meteor shower is known for producing many bright meteors.

While other astronomical events may have happened during August 1999, these two are likely the most well-known and significant.