Saturn’s largest moon Titan share many common traits with Earth from a thick atmosphere, rainfalls, lake and rivers to a rocky surface and plate tectonics. But new data from NASA’s Cassini orbiter show that another feature is common to the two rocky bodies – polar winds.
As it happens on Earth, Titan’s polar winds also pull gases out of the atmosphere and release them out into space. NASA scientists said that Saturn’s moon Titan is the first known space body to hold such winds on its surface, besides our planet.
NASA’s Cassini spacecraft has been analyzing Saturn for more than a decade. Since 2011, it performed 23 flybys, studied the planet’s atmosphere and monitored its magnetic field. Those observations allowed the probe gather more evidence on the existence of polar winds.
The particles of gas that were pushed out of the atmosphere by the polar winds were detected by Cassini’s Plasma Spectrometer (CAPS). CAPS spotted the particles by the charges they emitted during their flight.
NASA researchers explained that previous data from Cassini’s CAPS had showed that the Saturn’s atmosphere was losing nearly seven tons of nitrogen and methane on a daily basis, but no one knew exactly why that happened. The planet’s atmosphere contains mainly methane and nitrogen, while ground-level pressures are 50 percent higher than on Earth, the team said.
But new data provide an explanation for the dramatic loss. CAPS detected charged electrons of about 24 electron volts outside the planet’s atmosphere. Mission scientists realized that those charges could only be generated from a particle-sunray interaction.
“Although Titan is 10 times further from the sun than Earth is, its upper atmosphere is still bathed in light,”
noted Andrew Coates, lead author of the study and researcher at University College London’s Mullard Space Science Laboratory.
Prof. Coates also explained that hydrocarbon and nitrile particles from the moon’s ionosphere interact with sunlight, which deprives the particle of their negatively charged electrons leaving them positively charged.
The newly created electrons get later dragged across the planet’s magnetic field and arranged in an electric field which is powerful enough to attract the positively charged particles and push them out of the atmosphere, UCL scientists argued.
We have a similar process here on Earth. Charged particles travel along the magnetic field and escape the planet’s atmosphere at the poles. Though, scientists hold evidence only in Saturn’s case for the phenomenon, they believe that the process may happen on Venus and Mars, too.
The study was published June 18 in Geophysical Research Letters.
Image Source: RT