SEEING TITAN WITH INFRARED EYES
These six new infrared images of Saturn’s moon, Titan, just released by NASA represent some of the clearest, most seamless-looking global views of Titan’s surface produced so far.
Six new views of Titan were created using 13 years of data acquired by the Visual and Infrared Mapping Spectrometer (VIMS) instrument on board NASA’s Cassini spacecraft. The images are the result of a focused effort to smoothly combine data from the multitude of different observations VIMS made under a wide variety of lighting and viewing conditions over the course of Cassini’s twenty-year mission.
Previous VIMS maps of Titan display great variation in imaging resolution and lighting conditions, resulting in obvious seams between different areas of the surface. With the seams now gone, this new collection of images is by far the best representation of how the globe of Titan might appear to the casual observer if it weren’t for the moon’s hazy atmosphere, and it likely will not be superseded for some time to come.
NASA says it is quite clear from this unique set of images that Titan has a complex surface, sporting myriad geologic features and compositional units. The VIMS instrument has paved the way for future infrared instruments that could image Titan at much higher resolution, revealing features that were not detectable by any of Cassini’s instruments.
The Cassini-Huygens mission was conceived in 1982 as an international endeavor after two NASA Voyager spacecraft flew past the planet. The mission was a joint endeavor of NASA, the European Space Agency (ESA) and the Italian Space Agency. The Jet Propulsion Laboratory at the California Institute of Technology managed the mission for NASA’s Science Mission Directorate in Washington while the VIMS team was based at the University of Arizona in Tucson.
Launched on October 15, 1997, the mission entered orbit around Saturn on June 30, 2004. The European Huygens probe performed a detailed, up-close study of the planet, its rings and moons. In addition to Huygens’ dazzling revelations about Titan, the Cassini orbiter performed 127 of its own close flybys (with many more distant encounters). By the end of its four-year mission, the Cassini spacecraft had observed almost half of a Saturn year which is 29 earth-years long (the four seasons of Saturn’s year last about seven earth-years each). Following its initial, four-year tour, Cassini’s mission was extended two more years to enable the spacecraft to observe changes, particularly in the rings, as Saturn reached equinox and the sun shone edge-on to the rings.
Beginning in 2010, Cassini began a seven-year mission extension in which it completed many moon flybys while observing seasonal changes on Saturn and Titan. The Cassini spacecraft ended its remarkable journey of exploration in September 2017. Having expended almost every bit of its rocket propellant, operators deliberately plunged Cassini into the planet’s atmosphere so that it would burn up and disintegrate like a meteor. Called the Grand Finale, this final phase of the mission brought unparalleled observations of the planet and its rings from closer than ever before.
The findings of the Cassini mission revolutionized scientists’ understanding of Saturn, its complex rings, the amazing assortment of moons and the planet’s dynamic magnetic environment. The most distant planetary orbiter ever launched, Cassini started making astonishing discoveries immediately upon arrival – icy jets shoot from the tiny moon Enceladus, Titan’s hydrocarbon lakes and seas dominated by liquid ethane and methane, and complex pre-biotic chemicals in the atmosphere. Three-dimensional structures tower above Saturn’s rings, and a giant Saturn storm circled the entire planet for most of a year. Cassini’s findings at Saturn have also fundamentally altered many concepts about how planets form around stars.
