From the editor

A pride of lions silently patrolling the grassland at dusk; a cheetah closing in on its prey with mind-blowing speed; a watchful leopard curled artfully in a tree. There’s nothing quite like a big cat

THE MOST DOMINANT FORCE IN THE UNIVERSE IS ALSO ITS MOST MYSTERIOUS AND MOST UNANTICIPATED

Were the seeds of Civil War already written into the American Constitution?

From dark matter to deep-sea crabs, science still can’t fully explain these strange quirks of nature

TEERAYUT CHAISARN/GETTY AMBULATORY SURGERY CENTERS CONTINUE to ...

When to use this chart 1 December at 00:00 UT 15 December at 23:00 UT 31 December at 22:00 UT On other dates, stars will be in slightly different positions because of Earth’s orbital motion. Stars tha