Scientists discover giant ‘shadow’ creeping across Mars for 50 years but aren’t sure why
A mysterious dark “shadow” has been slowly spreading across the surface of Mars for nearly 50 years—and scientists still don’t fully understand why. First spotted in images taken by NASA’s Viking orbiters in 1976, the phenomenon has grown dramatically in size, raising new questions about how active—and unpredictable—the Red Planet really is. What makes this ...












