A recent study conducted by researchers at UCL (University College London Mullard Space Science Laboratory) reveals that Saturn’s moon Titan not only has seas, rivers, rainfall and now polar winds, but also rocky ground, a thick atmosphere and plate tectonics. The researchers say that Titan is the closest space object to the Earth that can be found inside our solar system.
Titan, Saturn’s largest moon, has been considered unique and fascinating for a while now. It’s similar to Earth and Venus, bigger than Mercury, and unlike any other moon that astronomers have stumbled upon to this day. It is the seconds most studied moon in the universe, right behind the Earth’s very own.
The findings come as a result of studying data collected by NASA’s Cassini spacecraft over the course of seven (7) years. The spacecraft started gathering information about Saturn back in 2004 and so far it has had 23 flybys through Titan’s atmosphere.
The information that Cassini’s Plasma Spectrometer (CAPS) provided researchers with signals that Titan’s atmosphere interacts with the solar magnetic field and the radiation in such a way that it creates a wind of hydrocarbons and nitriles that is blown into space from the moon’s polar regions.
Andrew Coates, study leader and member of the University College London Mullard Space Science Laboratory, gave a statement informing that “Titan’s atmosphere is made up mainly of nitrogen and methane, with 50 percent higher pressure at its surface than on Earth. Data from CAPS proved a few years ago that the top of Titan’s atmosphere is losing about seven tones of hydrocarbons and nitriles every day, but didn’t explain why this was happening. Our new study provides evidence for why this is happening”.
Hydrocarbons are molecules that re known to contain methane, as well as substances such as natural gas, petrol and bitumen, all elements known to contribute to life on Earth. Nitriles that have nitrogen and carbon closely bound together.
The team of researchers informs that this atmospheric loss is caused by polar winds that are aided by the interactions between the solar magnetic field, sunlight and molecules that can be found in the upper atmosphere.
Andrew Coates stresses that even though, when compared to the Earth, Titan is ten times further away from the Sun, the moon’s the upper atmosphere is still full of light.
He goes on to explain that once the light hits the molecules in Titan’s ionosphere, it sends negatively charged electrons out of the hydrocarbon and nitrile molecules, and leaves behind a positively charged particle. They are electrons known as photoelectrons, with a really specific energy of 24.1 electronvolts. This means that they can be traced by the CAPS instrument, and are very easy to distinguish from other electrons due to propagating through the surrounding magnetic field.
One big difference between Titan and planet Earth is that the moon has no magnetic field of its own. However, it is surrounded by Saturn’s magnetic field, which rotates very quickly and causes a comet-like tail to form around Titan.
The photoelectrons with a negative charge are spread throughout Titan’s ionosphere and the tail, and as a result set up an electrical field for the moon that is powerfull enough to pull positively charged hydrocarbons and nitriles from the atmosphere, spreading them all throughout the sunlit segment of the atmosphere, resulting in widespread polar winds.
The study was published earlier today (June 19, 2015) in the journal Geophysical Research Letters.
Image Source: dailygalaxy.com