Titan has similar atmosphere changes like Earth
28 September 2012: Saturn moon Titan shows huge seasonal change as Earth. Dr Athena Coustenis from the Paris-Meudon Observatory in France has analyzed data of Titan gathered over 30 years.
Coustenis analyzed data from several different missions, such as Voyager 1 (1980), the Infrared Space Observatory (1997), and Cassini (2004 onwards) which is also complemented by ground based observations.
Titan takes around 29.5 years to orbit the sun. So, now researchers have data gathered for an full Titan year covering all seasons in Titan. Each season on Titan spans around 7.5 years.
Coustenis explained, "As with Earth, conditions on Titan change with its seasons. We can see differences in atmospheric temperatures, chemical composition and circulation patterns, especially at the poles. For example, hydrocarbon lakes form around the north polar region during winter due to colder temperatures and condensation."
"Also, a haze layer surrounding Titan at the northern pole is significantly reduced during the equinox because of the atmospheric circulation patterns. This is all very surprising because we didn't expect to find any such rapid changes, especially in the deeper layers of the atmosphere," she added.
Solar energy, which is the dominant energy source for Titan's atmosphere, is the main cause of these atmospheric cycle. Solar energy breaks the nitrogen and methane present in Titan's atmosphere and create more complex molecules, such as ethane which act as the driving force for chemical changes.
Titan is inclined at around 27 degrees, which is close to inclination angle of the Earth. So, different areas in both Earth and Titan are illuminated by different amount of sunlight in different seasons due to this tilt resulting variation in weather in different seasons.
Coustenis said, "It's amazing to think that the Sun still dominates over other energy sources even as far out as Titan, over 1.5 billion kilometers from us".
Coustenis presented these results at the European Planetary Science Congress which is held in Madrid.
Coustenis explained that in Titan hydrocarbon lakes form around the north pole region during winter due to condensation and colder temperatures but at the northern pole a haze layer prevails which is significantly reduced during the equinox due for the atmospheric circulation patterns.
"This is all very surprising because we didn't expect to find any such rapid changes, especially in the deeper layers of the atmosphere," Coustenis said in the statement.
Coustenis explained why it is important to investigate this distant moon, "Titan is the best opportunity we have to study conditions very similar to our own planet in terms of climate, meteorology and Astro biology and at the same time a unique world on its own, a paradise for exploring new geological, atmospheric and internal processes."
Titan, which is Saturn's largest moon, is about 3,200 miles in diameter and is larger than the planet Mercury.