THE GREAT CONJUNCTION OF JUPITER AND SATURN: Want to see something that astronomers have been waiting 800 years to witness? Just step outside at sunset and look southwest. Jupiter and Saturn are having their finest conjunction since the Middle Ages--and they're bright. Bertrand Kulik sends this picture from Paris:"On Dec. 20th, the planets were visible right beside the Eiffel Tower," says Kulik. "It was a magical view!" At closest approach on Dec. 21st, the two planets will lie just 0.1 degrees apart. That’s so close, some people will perceive them as a single brilliant star. Viewed through binoculars or a...