Explore Saturn's largest moon, Titan

NARRATOR: We embark on a journey that will bring us a billion times closer to Titan’s surface. Titan is Saturn's largest moon, right in front of Saturn’s disc in this image taken by the Cassini spacecraft. Saturn’s atmosphere shows a banded structure and a number of storms. We view the edge of Saturn’s gigantic ring system. The rings cast major shadows onto Saturn’s southern hemisphere. Titan is surrounded by a partially transparent brown haze. Features on Titan’s surface appear. The dark regions along Titan’s equator are mostly dune fields. The brighter regions are highlands, a few hundred metres high. Images taken by the Huygens probe show Titan’s surface in more detail. The probe had spectrometers that measured small variations in the colour of Titan’s surface that are exaggerated here. Most of Titan’s surface is brown. North of the landing side, a pair of parallel dark dunes stretch east–west along the image. A large highland of triangular shape lies to the southwest. More and more dark canyons appear in this area. A complicated network of channels, where rivers of methane flowed at some time in the past. To the east of the landing site is a system of bright ridges, standing out above the dark, dry lake bed. The ridges have intricate structures that tell stories about their past. The Huygens probe descended towards one of these ridges. As we approach the surface further, we can see this ridge in finer detail. Some regions were imaged with high resolution just before Huygens landed on Titan, especially the area to the west of the landing site. Most of Titan’s surface is covered by dark organics that are produced in the atmosphere and slowly settle down. The bright spots may be exposed patches of water ice. The white dot in the centre of the image is the landed Huygens probe. While the probe rotated during the descent, its orientation after landing had the camera looking to the south. The camera saw a field of pebbles that were carried around by a river of methane in the past. Some pebbles are larger than a human hand. The Descent Imager/Spectral Radiometer is the dark green instrument at the south side of the Huygens probe. Its lamp illuminated the surface, allowing spectral analysis. The lamp’s spotlight stands out brightly since days on Titan are even darker than cloudy days on Earth. Little sunlight reaches Titan’s surface due to its thick haze and large distance from the Sun. The right side shows the green DISR instrument, with the gold-coloured lamp and the three camera windows to its right—the cameras that provided the first close-up view of Titan’s shrouded surface.