When was the Halley's Comet periodicity discovered?

More Questions:

In which sport would you be judged on your pike or your jack knife?

What's the "safest" color on the US Homeland Security Advisory System's color scale?

Who is the Greek equivalent of the Roman goddess Pax?

In which Shakespeare play does Antonio owe Shylock a pound of flesh?

What nation's legislative body is named The Knesset?

What US city's skyline boasts the Gateway Arch?

In what organ of the human body would you find the alveoli?

Who is Melanie Griffith's mother?

What was used to show blood in the shower scene from Psycho?

What TV title character has a rat named Steve McQueen?

What British TV series featured David Brent and Gareth Keenan?

In the Tom Petty song "Free Fallin'', the girl is a big fan of what singer?

Who played the role of the US president in the movie "Being There"?

What was the official US name for the 1991 Gulf War?

What year were the Canada's Juno Awards first awarded?