Exploring the Planets - Planetary Atmospheres

Cloudy Sky from the Surface of 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.

Storm in Saturn's Atmosphere

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Hubble Space Telescope Image courtesy
Space Telescope Science Institute.

Jupiter's Great Red Spot

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NASA Image #PIA00489
taken by the Galileo spacecraft.

Hurricane on Earth,
Fran off the SE Coast of North America

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Image produced by Laboratory for Atmospheres
NASA/Goddard Space Flight Center

Clouds
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.