Jupiter, its Red Spot, its banded atmosphere, and two of its moons in this view taken by the Voyager 1 spacecraft from about 20 million kilometers (12 million miles) away. Each moon is about the size of Earth’s moon. Meanwhile, Jupiter could contain more than a thousand Earths. The visible moons here are Io (left), is in front of the Red Spot, and Europa (right).

Deborah Byrd