In the late 1800s the red spot was an oval 25,500 miles (41,000 kilometers) wide. Now it's a circle that's 10,250 miles (16,500 kilometers) across.
Michael Wong, a scientist at the University of California, Berkeley, said the spot is a mystery. Astronomers don't know why it's red or shrinking, or what will happen next. If this pace continues, in 17 years the spot could be gone. Or it could stop at a smaller size.
Wong said one theory is the spot eats smaller storms, and that it is consuming fewer of them. AP