Titan: Complex ‘Anti-greenhouse’
This natural color image shows Titan’s upper atmosphere — an active place where methane molecules are being broken apart by solar ultraviolet light and the byproducts combine to form compounds like ethane and acetylene. The haze preferentially scatters blue and ultraviolet wavelengths of light, making its complex layered structure more easily visible at the shorter wavelengths used in this image.
A movie sequence of images, taken around the same time as this color view, shows movement of the haze layers over the course of a few hours (see PIA06223).
Lower down in the atmosphere, the haze turns into a globe-enshrouding smog of complex organic molecules. This thick, orange-colored haze absorbs visible sunlight, allowing only perhaps 10 percent of the light to reach the surface. The thick haze is also inefficient at holding in and then re-radiating infrared (thermal) energy back down to the surface. Thus, despite the fact that Titan has a thicker atmosphere than Earth, the thick global haze causes the greenhouse effect there to be somewhat weaker than it is on Earth.
Images taken with the Cassini spacecraft wide-angle camera using red, green and blue spectral filters were combined to create this natural color view. The images were obtained at a distance of approximately 9,500 kilometers (5,900 miles) from Titan on March 31, 2005. The image scale is approximately 400 meters (1,300 feet) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
New Insights into Titan’s Complex Chemistry
Cassini has made a surprising detection of a molecule that is instrumental in producing complex organics within the hazy atmosphere of Saturn’s moon Titan. In a new study published in The Astrophysical Journal Letters, scientists identified what are known as “carbon chain anions.” These linear molecules are understood to be building blocks of more complex molecules, and might even have acted as the basis for the earliest forms of life on Earth.
source: NASA – Jet Propulsion Laboratory – California Institute of Technology