Huygens’ view of the 1st landing on Titan

Ten years ago, ESA’s Huygens probe descended to the surface of Titan, Saturn’s largest moon.

Titan’s atmosphere even more Earth-like than previously thought

Scientists at UCL have observed how a widespread polar wind is driving gas from the atmosphere of Saturn’s moon Titan.

Schematic illustration of the magnetic connection between the sunlit ionosphere (left) and Cassini in the tail. Source: University College London

Celebrating 10 Years Since Titan Landing

Source: NASA

Ten years ago, an observer from Earth parachuted into the haze of an alien moon toward an uncertain fate. After a gentle descent lasting more than two hours, it landed with a thud on a frigid floodplain, surrounded by icy cobblestones. With this feat, the Huygens probe accomplished humanity’s first landing on a moon in the outer solar system. Huygens was safely on Titan, the largest moon of Saturn.

The hardy probe not only survived the descent and landing, but continued to transmit data for more than an hour on the frigid surface of Titan, until its batteries were drained.

Since that historic moment, scientists from around the world have pored over volumes of data about Titan, sent to Earth by Huygens – a project of the European Space Agency – and its mothership, NASA’s Cassini spacecraft. In the past 10 years, data from the dynamic spacecraft duo have revealed many details of a surprisingly Earth-like world.

Rivers of methane produced surprisingly little erosion on Titan

For many years, Titan's thick, methane- and nitrogen-rich atmosphere kept astronomers from seeing what lies beneath. Saturn's largest moon appeared through telescopes as a hazy orange orb, in contrast to other heavily cratered moons in the solar system.

The atmosphere of Titan is full of a thick haze, so it's impossible to take clear pictures of the surface in the optical wavelengths.

Titan flybys: How gravity assists work

For the past 18 months, NASA’s Cassini spacecraft has been orbiting Saturn in practically the same plane as the one that slices through the planet’s equator. Beginning with the Titan flyby on May 22, navigators started to tilt Cassini’s orbit in order to obtain a different view of the Saturnian system. The measure of the spacecraft orbit’s tilt relative to Saturn’s equator is referred to as its inclination. The recent Titan flyby raised Cassini’s inclination to nearly 16 degrees. Seven more Titan flybys will ultimately raise Cassini’s inclination to nearly 62 degrees by April 2013. On Earth, an orbit with a 62-degree inclination would pass as far north as Alaska and, at its southernmost point, skirt the latitude containing the tip of the Antarctic Peninsula.

It's been nearly two years since NASA's Cassini spacecraft has had views like these of Saturn's rings. These views are possible again because Cassini has changed the angle at which it orbits Saturn and regularly passes above and below Saturn's equatorial plane. Steeply inclined orbits around the Saturn system also allow scientists to get better views of the poles and atmosphere of Saturn and its moons. A group of scientists has restarted the team's studies of propeller-shaped gaps. These gaps are cleared out by objects that are smaller than known moons but larger than typical ring particles. Cassini scientists haven't seen propellers in two years. Because some of the propellers are exactly where models predicted they would be, scientists believe they are seeing some old friends again. Credit: NASA/JPL-Caltech/SSI/Cornell

Tropical lakes on Titan

The existence of oceans or lakes of liquid methane on Saturn's moon Titan was predicted more than 20 years ago. But with a dense haze preventing a closer look it has not been possible to confirm their presence. Until the Cassini flyby of July 22, 2006, that is. Radar imaging data from the flyby, published in the journal Nature, provide convincing evidence for large bodies of liquid. Intensity in this colorized image is proportional to how much radar brightness is returned, or more specifically, the logarithm of the radar backscatter cross-section. The colors are not a representation of what the human eye would see. The lakes, darker than the surrounding terrain, are emphasized here by tinting regions of low backscatter in blue. Radar-brighter regions are shown in tan. Smallest details in this image are about 500 meters (1,640 feet) across. Credit: NASA/JPL-Caltech/USGS