Exploring the Planets


Even though Mars’ atmosphere is less than one-hundredth as dense as Earth’s, the behavior of winds and clouds can be relatively similar on both planets.

Counds Over Mars

Image courtesy NASA/JPL/Caltech taken by the Mars Pathfinder Lander.

Water Ice Clouds on Mars

Hubble Space Telescope image courtesy Space Telescope Science Institute.


Although the atmospheres of the terrestrial planets and the gaseous planets are composed of different gases, atmospheric circulation patterns can have some characteristics in common. Like the terrestrial planets, atmospheres of the gas giants can change dramatically over time. The Great Red Spot on Jupiter is a storm that has been observed through telescopes for more than 300 years. While the Spot itself has never disappeared, circulation patterns within the Spot are constantly changing. Although hurricane-like in nature, at 40,000 kilometers (25,000 miles) across, the Great Red Spot is on a much larger scale than Earth storms. For example, the eye of hurricane Fran was about 24.9 kilometers (15.5 miles) across.

Saturn's Storm

The huge storm churning through the atmosphere in Saturn's northern hemisphere overtakes itself as it encircles the planet in this true-color view from NASA's Cassini spacecraft.

Jupiter's Great Red Spot

This Voyager 2 picture shows the Great Red Spot and the south equatorial belt extending into the equatorial region.

Hurricane Fran, off the SE coast of North America

The GOES weather satellites took this image of Hurricane Fran just as it was beginning its disastrous journey north along the East Coast in 1996.