Science: The Big Cover-Up

North America's last solar eclipse of the century (right) was obscured by a cold gray cloud cover along much of the path of totality. But eclipse buffs near Roundup, Mont, (left), and other viewing areas in the U.S. Northwest and Canada were luckier. Armed with telescopes, cameras and other paraphernalia, they let out joyful whoops under mostly clear skies as the moon's shadow raced toward northern Greenland. It was an all too brief show—as long as 2 min. 36 sec. in Helena, Mont., less than a minute elsewhere—and a rare one. It will be a spell until the next U.S. performance:...