Explore the Night with Bob King

Don't Miss Monday's Rare Transit of Mercury

On Monday, November 11th, Mercury will pass directly in front of the Sun and look a tiny black dot silhouetted against the brilliant solar disk. The event, called a transit, occurs approximately 13 times a century.

Celestial News & Events

What is the Black-Drop Effect?

The famous (or infamous) black-drop effect earned its place in history long before astronomers knew what caused it.

Celestial News & Events

The Disappearing Black Drop

When you observe the upcoming transit of Venus on June 5th or 6th, will you see the black drop?

black drop

Where Was the Black Drop?

Reports around the world vary dramatically as to the reality of a black-drop effect during the Venus transit.