
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.
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.
The Disappearing Black Drop
When you observe the upcoming transit of Venus on June 5th or 6th, will you see the 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.