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‘Waves’ detected on Titan moon’s lakes – Scientists detect waves on another world for the first time

We are detecting waves on a world 1,272,000,000 km away from Earth.

An interesting world

The signature of isolated ripples was observed in a sea called Punga Mare on the surface of Saturn’s moon Titan; but before you get overly excited, you should know that these seas are not filled with water, but with hydrocarbons like methane and ethane.

Titan is one strange place; it’s a satellite, but it’s bigger than Mercury. It’s also the only place in our solar system where evidence of liquid has been found on the surface, but wait, it gets even better – researchers believe that there is also an underground ocean, which might harbor life.

If you look at it a little, Titan has a lot in common with Earth. It has an atmosphere and seasonal cycles, river channels modeled by wind and rain, seas, dunes and even shorelines. But if you look at it even closer, you’ll also see just how different it is from our planet. The surface temperature on Titan is about -180degrees Celsius (-292 Fahrenheit). Its landforms are made of ice, rather than rock or sand, and liquid hydrocarbons take up many of the roles played by water on Earth. Just so you can get a sense of scale, one of these seas, Ligeia Mare, is estimated to contain about 9,000 cubic km of mostly liquid methane – about 40 times the proven reserves of oil and gas on Earth.

Titanic waves

An image of Titan’s north pole taken by the Cassini probe during a flyby in July 2012 shows sunlight being reflected from surface liquid in much the same way as a mirror re-directs light. The phenomenon is called specular reflection, and interestingly enough, has been described 2.000 years ago. Analyzing this reflection, scientists believe they can identify waves on the surface of Titan. Specifically, Dr Barnes, from the University of Idaho in Moscow, US, used a mathematical model to analyze the reflections, and showed that they are compatible with waves.

“We think we’ve found the first waves outside the Earth,” he told the meeting. What we’re seeing seems to be consistent with waves at just a few locations in Punga Mare [with a slope] of six degrees.”

This is not an absolute certainty, as he says that other causes such as a wet mudflat, could not be ruled out. But if they are indeed waves (as it seems more likely), the wind speed is estimated at about 0.75 m/s – a mere breeze. The waves are also estimated to be just 2cm high.

“Don’t make your surfing vacation reservations for Titan just yet,” Dr Barnes jokes.

However, as I said above, Titan also has seasonal changes – and pretty soon, it will undergo one. The winds are expected to intensify as this mysterious world will change season.

“The expectation is that any day now, the winds will start getting strong enough as we move into northern summer, and the waves will start picking up,” Ralph Lorenz, from the Johns Hopkins Applied Physics Laboratory (JHUAPL) in Maryland, told ZME Science. “You can also get a phenomenon known as wind set-up, where wind over a body of water will cause the liquid to pile up, potentially causing a storm surge.”

Weather on Titan

Artistic vision of weather on Titan.

Computer models of Titan’s weather suggest that in the norther hemisphere, the dry season is drawing closer to an end, and it’s almost rainy season. What happens during the rainy season? Hydrocarbons are “pumped” from the south pole to the north by the climate cycle, and, well, it will start raining hydrocarbons.

“We have a long-term picture of liquid levels rising in the north and declining in the south. But that’s against the backdrop of seeing what we think are evaporite deposits around the northern seas and lakes,” Dr Lorenz explained.

Astrophysicists and geophysicists are starting to put together more and more pieces of the puzzle… but it’s a really complicated puzzle. But one thing’s for sure – the liquids play a key role.

“Everything is really starting to come together, and the seas and lakes are very much becoming the central topic in Titan science.”

Ingredient of Household Plastic Found on Saturn Moon

NASA’s Cassini spacecraft has detected propylene, a chemical used greatly in everyday life, in things like food-storage containers, car bumpers and other consumer products, on Saturn’s Moon Titan. I really recommend watching the video below, as it explains the situation in great detail:

A small amount of propylene was identified in Titan’s lower atmosphere by Cassini’s Composite Infrared Spectrometer (CIRS); the device measures infrared emissions given away by Saturn and Saturn’s moons in a similar way to the way our hands feel a fire’s warmth. Every gas has a unique thermal fingerprint, and based on that, CIRS can identify pretty much every gas. The only problem is isolating the signal from other, interfering signals.

“This measurement was very difficult to make because propylene’s weak signature is crowded by related chemicals with much stronger signals,” said Michael Flasar, Goddard scientist and principal investigator for CIRS. “This success boosts our confidence that we will find still more chemicals long hidden in Titan’s atmosphere.”

This detection brings a valuable piece of the puzzle, a piece which was sought after since the Voyager 1 spacecraft and the first-ever close flyby of this moon in 1980. Voyager identified many of the gases in Titan’s hazy brownish atmosphere as hydrocarbons, a class of organic chemical compounds composed only of the elements carbon (C) and hydrogen (H) which compose most of the petroleum and natural gas.

False-color images, made from data obtained by NASA's Cassini spacecraft, shows clouds covering parts of Saturn's moon Titan in yellow.

False-color images, made from data obtained by NASA’s Cassini spacecraft, shows clouds covering parts of Saturn’s moon Titan in yellow.

In Titan’s atmosphere, hydrocarbons form after sunlight breaks apart methane, the second-most plentiful gas in that atmosphere. The new fragments can bond together, forming chains of 2, 3, or even more carbons – ethane and propane for example, can be created this way.

As Cassini continued to discover more and more hydrocarbons on Titan, propylene remained elusive until the CIRS analysis.

“I am always excited when scientists discover a molecule that has never been observed before in an atmosphere,” said Scott Edgington, Cassini’s deputy project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “This new piece of the puzzle will provide an additional test of how well we understand the chemical zoo that makes up Titan’s atmosphere.”

For more information on the Cassini mission, visit NASA’s page.


What is Titan — Saturn’s moon



This is Saturn’s Moon – the largest moon of Saturn, the only moon known to have a dense atmosphere and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found – and these are just a few of the reasons which make studying it more than worthwhile.

It is geologically young and the climate includes methane and ethane clouds. Titan was discovered on March 25, 1655, by the Dutch astronomer Christiaan Huygens. Huygens was inspired by Galileo’s discovery of Jupiter’s four largest moons in 1610 and his improvements on telescope technology. But he probably did not suspect how much it resembles our planet in some ways, and how could he?.

Titan is the only known moon with a fully developed atmosphere that consists of more than just trace gases. Titan’s temperature is about 94 K (−179 °C, or −290.2 °F) at the surface. At this temperature water ice does not sublimate from solid to gas, so the atmosphere is nearly free of water vapor. “You have all these things that are analogous to Earth. At the same time, it’s foreign and unfamiliar,” said Ray Pierrehumbert, the Louis Block Professor in Geophysical Sciences at Chicago.

So it is hard to understand how it resembles our planet since we have not landed there and we probably are not going to for many years. But telescopes and the Cassini–Huygens spacecraft provide interesting and important information about it. “The ironic thing on Titan is that although it’s much colder than Earth, it actually acts like a super-hot Earth rather than a snowball Earth, because at Titan temperatures, methane is more volatile than water vapor is at Earth temperatures,” Pierrehumbert said.

“This is a well-known feature on Earth called an ITCZ, the inter-tropical convergence zone,” Mitchell said. Earth’s oceans help confine the ITCZ to the lowest latitudes. But in some scenarios for oceanless Titan, the ITCZ in Mitchell’s computer simulations wanders in latitude almost from one pole to the other. Titan’s clouds should also follow the ITCZ. Titan’s orange atmospheric haze complicates efforts to observe the moon’s clouds.

“This haze shrouds the entire surface,” Mitchell said. “It pretty much blocks all visible light from reaching us from the surface or from the lower atmosphere.”. But scientists can use theories which apply to our planet.

“Titan is like a big petrochemical plant,” Pierrehumbert said. “Although this is all happening at a much lower temperature than in a petroleum refinery, the basic processes going on there are very closely allied to what people do when they make fuel.”