Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surface of Titan Sea is mirror smooth, Stanford scientists find

20.03.2014

New radar measurements of an enormous sea on Titan offer insights into the weather patterns and landscape composition of the Saturnian moon.

The measurements, made in 2013 by NASA's Cassini spacecraft, reveal that the surface of Ligeia Mare, Titan's second largest sea, possesses a mirror-like smoothness, possibly due to a lack of winds.


This false-color image of the surface of Titan was made using radar measurements made by NASA's Cassini spacecraft. The spacecraft revealed that the surface of Ligeia Mare, Titan's second largest lake, is unusually still, most likely due to a lack of winds at the time of observation.

Credit: Courtesy of Howard Zebker

"If you could look out on this sea, it would be really still. It would just be a totally glassy surface," said Howard Zebker, professor of geophysics and of electrical engineering at Stanford who is the lead author of a new study detailing the research.

The findings, recently published online in Geophysical Research Letters, also indicate that the solid terrain surrounding the sea is likely made of solid organic materials and not frozen water.

Saturn's second largest moon, Titan has a dense, planet-like atmosphere and large seas made of methane and ethane. Measuring roughly 260 miles (420 km) by 217 miles (350 km), Ligeia Mare is larger than Lake Superior on Earth. "Titan is the best analog that we have in the solar system to a body like the Earth because it is the only other body that we know of that has a complex cycle of solid, liquid, and gas constituents," Zebker said.

Titan's thick cloud cover makes it difficult for Cassini to obtain clear optical images of its surface, so scientists must rely on radar, which can see through the clouds, instead of a camera.

To paint a radar picture of Ligeia Mare, Cassini bounced radio waves off the sea's surface and then analyzed the echo. The strength of the reflected signal indicated how much wave action was happening on the sea. To understand why, Zebker said, imagine sunlight reflecting off of a lake on Earth. "If the lake were really flat, it would act as a perfect mirror and you would have an extremely bright image of the sun," he said. "But if you ruffle up the surface of the sea, the light gets scattered in a lot of directions, and the reflection would be much dimmer. We did the same thing with radar on Titan."

The radar measurements suggest the surface of Ligeia Mare is eerily still. "Cassini's radar sensitivity in this experiment is one millimeter, so that means if there are waves on Ligeia Mare, they're smaller than one millimeter. That's really, really smooth," Zebker said.

One possible explanation for the sea's calmness is that no winds happened to be blowing across that region of the moon when Cassini made its flyby. Another possibility is that a thin layer of some material is suppressing wave action. "For example, on Earth, if you put oil on top of a sea, you suppress a lot of small waves," Zebker said.

Cassini also measured microwave radiation emitted by the materials that make up Titan's surface. By analyzing those measurements, and accounting for factors such as temperature and pressure, Zebker's team confirmed previous findings that the terrain around Ligeia Mare is composed of solid organic material, likely the same methane and ethane that make up the sea. "Like water on Earth, methane on Titan can exists as a solid, a liquid, and a gas all at once," Zebker said.

Titan's similarities to Earth make it a good model for our own planet's early evolution, Zebker said. "Titan is different in the details from Earth, but because there is global circulation happening, the big picture is the same," he added. "Seeing something in two very different environments could help reveal the overall guiding principles for the evolution of planetary bodies, and help explain why Earth developed life and Titan didn't."

###

Ker Than is associate director of communications for the Stanford School of Earth Sciences.

Ker Than, Stanford | EurekAlert!

Further reports about: Cassini Earth Surface Titan ethane materials measurements mirror smooth smoothness terrain waves winds

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>