NASA Cassini Titan Research: Ice On A Hydrocarbon Lake

This artist's concept envisions what hydrocarbon ice forming on a liquid hydrocarbon sea of Saturn's moon Titan might look like. 

A new model from scientists on NASA's Cassini mission suggests that clumps of methane-and-ethane-rich ice could float under some conditions. They are shown here as the lighter-colored clusters.

A new paper by scientists on NASA's Cassini mission finds that blocks of hydrocarbon ice might decorate the surface of existing lakes and seas of liquid hydrocarbon on Saturn's moon Titan.

The presence of ice floes might explain some of the mixed readings Cassini has seen in the reflectivity of the surfaces of lakes on Titan.

"One of the most intriguing questions about these lakes and seas is whether they might host an exotic form of life," said Jonathan Lunine, a paper co-author and Cassini interdisciplinary Titan scientist at Cornell University, Ithaca, N.Y.

"And the formation of floating hydrocarbon ice will provide an opportunity for interesting chemistry along the boundary between liquid and solid, a boundary that may have been important in the origin of terrestrial life."

Titan is the only other body besides Earth in our solar system with stable bodies of liquid on its surface. But while our planet's cycle of precipitation and evaporation involves water, Titan's cycle involves hydrocarbons like ethane and methane.

Ethane and methane are organic molecules, which scientists think can be building blocks for the more complex chemistry from which life arose.

Cassini has seen a vast network of these hydrocarbon seas cover Titan's northern hemisphere, while a more sporadic set of lakes bejewels the southern hemisphere.

Titan: The rover boat that could explore Saturn's moon

Mars may grab all the headlines, but the Red Planet isn't the only Earth-like body in our solar system.

Saturn's moon Titan has long sparked the interest of scientists because its surface is covered in lakes, and rivers — which are filled with liquid methane.

Now, a group of engineers have submitted their plans for a new kind of rover — a floating space boat to rival NASA's Curiosity.

The Titan Lake In-situ Sampling Propelled Explorer, or TALISE, would succeed the ESA's Huygens probe, which touched down on Titan in 2005 after a seven-year journey.

TALISE would weigh about 100 kilograms (220.5 lbs), and would be equipped with an assortment of scientific instruments including a magnetometer, a panoramic camera, an acoustic sounder and a Light Detection And Ranging (LiDAR) system.

It would move across the surface of the liquid hydrocarbons using either smooth wheels, paddle wheels, or screw drives – all three systems are currently being considered.

Earlier ideas that were ultimately rejected included tank tracks, above- and below-surface propellers, and a hovercraft design.

After landing, TALISE will explore and collect data from the liquid methane makeup of the lakes found on the moon's surface.

SENER, a private aerospace company, is working in collaboration with Spain's Centro de Astrobiologia to develop a propulsion system that would allow TALISE to navigate on both land and sea, using a combination of wheels and paddles.

NASA Cassini: Seasonal changes on Saturn

A blue hue appears in Saturn's southern hemisphere as winter approaches. Credit: NASA/JPL-Caltech/SSI

Three of the most recent images show Saturn’s largest moon, Titan, and the recently discovered vortex in the atmosphere at the south pole.

The visible light cameras on Cassini have been monitoring a strange yellow haze in the detached haze layer at Titan’s south pole since 27 March.

The visual and infrared spectrometers then detected clouds building up in the region on 22 May.

When Cassini flew by Titan on June 27, 2012, it was found that the vortex is spinning faster than the moon itself is rotating.

The views of the vortex are only possible because Cassini is on a new orbit that is tilted, which enables it to get a better look at the polar regions of both Saturn and its moons.

"Cassini has been in orbit now for the last eight years, and despite the fact that we can't know exactly what the next five years will show us, we can be certain that whatever it is will be wondrous," explains Carolyn Porco.

The south polar vortex is visible in this image. Credit: NASA/JPL-Caltech/SSI 

Cassini is currently in its second mission extension, which has been called the Solstice Mission, and monitoring the seasonal changes on the ringed planet is one of the main objectives at the moment.

"It is so fantastic to experience, through the instruments of Cassini, seasonal changes in the Saturn system," said depute project scientist Amanda Hendrix.

"Some of the changes we see in the data are completely unexpected, while some occur like clockwork on a seasonal timescale. It's an exciting time to be at Saturn."

NASA Cassini Image: Saturn's Moons - Giant Titan and tiny Tethys

The Cassini spacecraft watches a pair of Saturn's moons, showing the hazy orb of giant Titan beyond smaller Tethys. 

This view looks toward the Saturn-facing sides of Titan (3,200 miles, or 5,150 kilometers across) and Tethys (660 miles, or 1,062 kilometers across).

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Oct. 18, 2010. 

The view was obtained at a distance of approximately 1.6 million miles (2.5 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 55 degrees. 

The view was obtained at a distance of approximately 930,000 miles (1.5 million kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 55 degrees. 

Image scale is 15 kilometers (9 miles) per pixel on Titan and 6 miles (9 kilometers) per pixel on Tethys.

Image Credit: NASA/JPL/Space Science Institute