Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mysterious features spotted on Titan reveal the moon's seasonal changes, says Stanford scientist

30.06.2014

Bright spots in a large lake on Titan suggest that Saturn's largest moon supports processes similar to Earth's water cycle, says Howard Zebker.

At first glance, Titan has little in common with Earth. The largest moon of Saturn, temperatures on Titan's surface dip nearly 300 F below zero, its seas slosh with liquid methane, and its sky is a murky shade of creamsicle.


Using data collected by Cassini's radar instruments, scientists have observed changes in Titan's liquid methane lakes and seas that indicate the moon experiences seasonal changes. (Image: NASA/JPL-Caltech)

And yet, fresh analysis of mysterious features spotted on the moon indicates that it experiences one of the same global processes that is important here on Earth.

In a study published in the latest issue of Nature Geoscience, scientists operating the Cassini satellite, including Stanford's Howard Zebker, present evidence that Titan has seasonal cycles analogous to Earth's, and that the moon's surface conditions change as the Titan year unfolds.

The Cassini satellite has been orbiting Saturn and its moons since 2004. Zebker, a professor of electrical engineering and of geophysics, is one of the lead scientists operating the spacecraft's radar instruments. Radar is critical for studying Titan in particular because the moon's atmosphere is typically too cloudy and thick for optical instruments to see through easily.

During five fly-bys of Titan's Ligeia Mare – a liquid methane sea larger than Lake Superior – the scientists noticed bright features that appeared and changed shape on the sea's surface. After ruling out a technical glitch or an exotic artifact of radar scattering, the group focused on three causes most likely for the phenomena.

"We are driven to use our imaginations and picture what could be happening on the sea to produce a transient feature," Zebker said.

One such explanation could involve low-density solids that usually sink below the surface – much like silt in a river delta – but then rise and clump together. Unlike ice on Earth, frozen methane is denser than its liquid phase, so it sinks instead of floats. "On Earth, ice floats and we get icebergs," Zebker said. "On Titan, icebergs would sink."

Seasonal temperature changes could account for the appearance and disappearance of these solids, as they might be released from the bottom and rise to the surface in warmer temperatures.

A second explanation involves bubbles. As summer temperatures warm the sea, bubbles trapped by the sunken frozen material could be released and float to the surface.

Finally, the bright features could be cresting waves, whipped up by summer winds.

"Waves are usually not visible on Titan, but in this case the onset of the summer season may create a more turbulent atmosphere," Zebker said. "On Earth we see this effect as the ocean warms and we start a new hurricane season."

A global cycle

All together, the observation and the possible explanations suggest that Titan's surface changes seasonally. They also support the idea that liquid methane might flow and evaporate in response to changing exposure to sunlight, in much the same way that water cycles through various systems on Earth.

Liquid methane lakes and seas have been observed on Titan's surface, and the atmosphere appears to carry methane and ethane similar to the way that Earth's atmosphere transports water vapor, Zebker said, and so scientists can expect Titan to have variations in liquid methane, ethane and other hydrocarbons driven by changes in temperature and sunlight.

As with any discovery that compares an alien world to Earth, the question of "Can it support life?" must be addressed. Although a dynamic process like the methane cycle and seasons go hand-in-hand with life on Earth, Zebker said that this discovery didn't significantly increase the chances that this moon of Saturn might support life.

"If there is sufficient energy pumped into Titan's atmosphere and surface from the sun, then it is possible that this would spawn evolution of life forms that take advantage of the energy source," Zebker said. "It would be very different life than on Earth, as it is minus 292 degrees Fahrenheit most of the time. Still, Titan remains one of the best places for life to evolve in the solar system."

Media Contact

Howard Zebker, Electrical Engineering and Geophysics: zebker@stanford.edu

Bjorn Carey, Stanford News Service: (650) 725-1944, bccarey@stanford.edu

Howard Zebker | Eurek Alert!
Further information:
http://news.stanford.edu/news/2014/june/titan-moon-seasons-062614.html

Further reports about: Cassini Earth Geophysics Geoscience Saturn Superior Titan atmosphere bubbles satellite temperature waves

More articles from Earth Sciences:

nachricht Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University

nachricht NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

Two-dimensional melting of hard spheres experimentally unravelled after 60 years

24.04.2017 | Life Sciences

Molecular libraries for organic light-emitting diodes

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>