NASA scientists recently found some surprises after looking over new maps of Saturn's moon Titan. On these maps, traces of gases near its north and south poles shine brightly during the moon's dusk and dawn, revealing new insight into the chemical composition of Titan's atmosphere.
So why are we so interested in Titan's atmosphere? Titan's atmosphere is affected by the sun's energy, as well as Saturn's magnetic field. This creates carbon-based molecules. Scientists believe that Titan's modern-day atmosphere is very similar to Earth's early atmosphere, so in understanding Titan, we can understand an earlier version of our planet.
Data from the Atacama Large Millimeter/submillimeter Array (ALMA) created the new maps of Titan. The telescope is sensitive enough to create images of the chemical composition of Titan's atmosphere from a "snapshot" it took of the moon.
In the maps, areas of gases shone brightly in the moon's atmosphere, specifically near its north and south poles.
Researchers studied these maps and looked at specific molecules within the gases: hydrogen isocyanide (HNC) and cyanoacetylene (HC3N). They found each in specific pockets at Titan's poles at lower altitudes, something that lines up with what NASA's Cassini spacecraft also observed.
What surprised researchers about this new finding, though, is that when they compared the concentrations of these gases at higher altitudes, the pockets of gases shifted away from the poles. This seems unlikely because Titan has heavy winds that move in an east-west direction, which would mix up the gases in the upper atmosphere, rather than keep them separated in pockets.
"It seems incredible that chemical mechanisms could be operating on rapid enough timescales to cause enhanced 'pockets' in the observed molecules," says Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center. "We would expect the molecules to be quickly mixed around the globe by Titan's winds."
As of now, scientists have no explanation for this phenomenon. It could be caused by unknown thermal effects, as well as unknown atmospheric patterns around Titan. There's also a chance Saturn's magnetic field is playing a part in this mystery, as it does extend as far as Titan.
"This is an unexpected and potentially groundbreaking discovery," says Martin Cordiner from NASA's Goddard Space Flight Center. "These kinds of east-to-west variations have never been seen before in Titan's atmospheric gases. Explaining their origin presents us with a fascinating new problem."
