« Jupiter	Uranus »
	Titan At a Glance
	Discovery 1655, Christiaan Huygens Diameter 3,200 miles 5,150 km Distance from Saturn 745,000 miles 1.2 million km Orbital Period 16 days Compare Moons

Surrounded by a thick atmosphere that's topped by orange smog, and with a landscape that in some ways resembles Earth, Titan is one of the solar system's most intriguing moons.

Cassini’s instruments peered through Titan’s clouds to reveal its surface.

Scientists had expected to find large seas or oceans of liquid methane, but Cassini found that there may be only a few small bodies of liquid. The Huygens probe, which parachuted through Titan's atmosphere in early 2005, photographed a landscape that, in some ways, is similar to Earth's, with possible drainage channels carved into hillsides. Huygens' instruments also found a thin layer of ice coating the surface at its landing site.

Titan's surface consists of rock and ices. Volcanoes may belch methane into the atmosphere, contributing to the moon's smog layer.

Tracking Titan's Temperature
As the Huygens probe parachuted through the atmosphere of Saturn's moon Titan in January 2005, it took the first direct measurements of temperatures, wind speeds, and the atmosphere's composition. Yet it sampled only one small region on one day. To fully understand Titan's complex atmosphere, scientists must study the entire moon, and repeat their observations to see how it changes over time.

 

Top: Cassini view of Titan shows the orange layer of smog near the top of its atmosphere, with a thin purple haze layer above it. Above: A close-up view of the haze layer. The atmosphere gets denser from right to left, with the body of Titan well outside the image to the left.

Trafton was using a Texas-built spectrograph, TEXES, to study the molecule cyanoacetylene. This organic molecule is of particular interest because it contains nitrogen, which is one of the ingredients of amino acids, which are some of the "building blocks" of life. The early Earth probably contained similar molecules, so studying them on Titan could yield new information about the atmospheric conditions that led to life on Earth. The molecule also provides a look at temperatures in Titan's upper atmosphere across the entire moon. The Texas researchers found that the temperatures were a little lower than expected. But their observations, which covered primarily the southern hemisphere of Titan, were similar to those of the Voyager 2 spacecraft, which studied Titan's northern hemisphere when it flew past Saturn more than two decades ago.

Their data will form part of the overall picture of Titan that is emerging from Huygens and the Cassini orbiter, with support from astronomers at McDonald and other observatories on Earth.

Keywords