An icy sheet covers nearly halfway around Titan, Saturn's largest moon. The long corridor of bare ice spans 6,300 kilometers or 3,914 miles.
A team of researchers from the University of Arizona Lunar and Planetary Laboratory discovered this ice belt near Titan's equator while looking for the source of the moon's methane. This new revelation follows the recent discovery of "eerie or phantom lakes" on the Titan's surface.
Ice And Methane On Titan
According to the study published in the journal Nature, the linear ice corridor detected on steep slopes that wraps around 40 percent of Titan's circumference doesn't correlate with any surface features nor any measurements of the moon's subsurface. The study also suggests that the icy corridor is currently eroding and could be unveiling the presence of ice and other organic strata.
"Given that our study and past work indicate that Titan is currently not volcanically active, the trace of the corridor is likely a vestige of the past," said Caitlin Griffith, a researcher at UA and lead author of the study.
Using thousands of spectral data captured by NASA spacecraft Cassini's Visible and Infrared Mapping Spectrometer, Griffith and her team used principal components analysis in an unconventional way to further study the composition of Titan's surface. The Cassini-Huygens mission first observed the Titan atmosphere's chemical composition and surface properties more than a decade ago. Succeeding studies confirmed the presence of methane on Titan.
Titan is covered in orange haze composed of seas of methane and an atmosphere full of organic molecules. Except for a few wavelengths of light that can penetrate the haze, it is difficult to see the Titan's surface because of the thick, golden atmosphere.
Principal Components Analysis Method
The Principal Components Analysis or PCA method used by Griffith's team was able to detect even the weak surface features. They used all the pixels in the spectral images to recognize the main and subtle signatures instead of measuring the surface features individually for each pixel in an image.
They compared their results with past studies including the Huygens probe, which landed on Titan in 2005. The comparison validated both the technique and the results. The researchers said they are planning to use the same method to explore Titan's poles where the methane seas are located.
Aside from the linear ice corridor, the scientists also found a specific icy area surrounding a 500-meter-high mountain called Doom Mons and a neighboring pit measuring 1,500 meters deep. The new research also validated previous studies made on the Titan.
Hazy Moon Titan
Titan is the second largest moon in the solar system. It is very similar to the Earth particularly with the seasonal changes, rain, and surface lakes and seas. Its atmosphere is mainly nitrogen and a small amount of methane.
A recent separate study looked into the moon's polar vortex and discovered that Titan's summer solstice lasts up to three-quarters of a Titan year, or approximately 22 Earth years.
