At lift off, US space shuttles weight about 4.5 million pounds.

In 1967, the IMAX film system was invented by Canadian Ivan Grame Ferguson to premier at Expo 67.

Mark Twain was born on a day in 1835 when Halley's Comet came into view. When he died in 1910, Halley's Comet was in view again.

AMAZING FACTS