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This web page's content and links are no longer actively maintained. It is available for reference purposes only. NASA Official: Dr. Paul Mahaffy

Gas Chromatograph Mass Spectrometer

Titan: Behind the Orange Haze

Basic Properties


Titan is the second largest moon in the Solar System; with a diameter of 5150 km (3,200 miles), it is just slightly smaller than Jupiter's moon Ganymede. Half of Titan is comprised of water ice and half is comprised of rocky material. Although considered to be a moon, Titan is bigger than 2 planets of our Solar System - it is larger in diameter than Mercury and more massive than Pluto.

The Atmosphere

The surface of Titan is shrouded by a dense atmosphere, comprised primarily of nitrogen and methane with traces of argon and hydrocarbons. The organic (carbon-based) compounds are formed as the methane is destroyed by sunlight. The result is Titan's signature orange haze - very similar to smog on Earth, only thicker.

Titan's atmosphere is actually 50% denser than Earth's, and visible light cannot penetrate it. As a result, when Voyager 1 flew past in Novemeber of 1980 and tried to take photographs, all that scientists could discern from the pictures were thick clouds and an orange haze.

Scientists hypothesize that Titan's atmosphere is comprised as the diagram below:

Titan's Atmospheric Layers
Titan's Atmospheric Layers

The Surface

Titan's surface is a mystery to scientists. They do know it is not homogeneous - it is not uniform in its composition. There is much debate over whether or not the surface is comprised of dry land, oceans of hydrocarbons, or slush.

Hubble Telescope Pictures
Recent Hubble Telescope Pictures of Titan's Surface

The surface temperature is around 94 K (-290 degrees Fahrenheit), which is too cold for liquid water to exist. In order for liquid water to exist on Titan, it would have to be thermally insulated underneath a layer of ice.

What Scientists Hope to Learn

With its methane-rich, nitrogen-based atmosphere and clouds made of complex organic molecules, Titan possesses conditions similar to the conditions on Earth before life began. By studying and understanding Titan's atmosphere, scientists aim to understand how life evolved on Earth.

Interesting Links About Titan


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