A team of researchers headed by Dr Ellen Stofan, have submitted a proposal to NASA for a mission that would see some kind of vehicle exploring Ligeia Mare, a lake of liquid methane in the North of Titan. According to Stofan, such a mission wouldn't just help scientists understand the chemical composition of the lake itself, but also the ecosystem of the moon and inspire non-science geeks by harkening back to simpler times:

It is something that would really capture the imagination... The story of human exploration on Earth has been one of navigation and seafaring, and the idea that we could explore for the first time an extraterrestrial sea I think would be mind-blowing for most people.

The proposal is expected to be submitted in the next few months, and we hope that NASA sees the potential in a return to blowing people's minds with science. Or, at least, the potential in space piracy on the methane seas.

'Boat' could explore Saturn moon [BBC News]

Scientists at Caltech think they may have uncovered the reasons for Titan's extremely odd lake arrangement. Data gathered by the Cassini orbiter showed 20 times more area in the Northern extremities were covered by liquid ethane and methane, when compared to the South. The researchers, headed by Oded Aharonson, think that the transport of methane northwards may be due to the elliptical orbit of Saturn, and hence Titan.

Over the course of one Titan year (29.5 Earth years), the Northern hemisphere summer is long and mild, but the Southern hemisphere version is short and intense. That's because in the Southern summer season Titan is around 12% closer to the sun. While this doesn't make a huge difference over the course of a year, it does over a longer time period: It's possible that these uneven seasons result in methane evaporating in the south, drifting northward in the clouds, and then raining prodigiously in the milder north.

Around 32,000 years ago, the situation would have been reversed, with the hydrocarbons traveling Southward instead of North.

This theory is being published in this month's Nature Geoscience. Other possible explanations for the lakes include the idea that there is some (as yet unknown) fundamental difference between the hemispheres. It's also possible the methane transfer happens every season, not gradually.

The Titan Saturn System Mission, a joint endeavor between NASA and the European Space Agency, hopes to launch probes to Titan by 2020 with the aim of better understanding the seas, atmosphere, surface composition and subterranean dynamics of Saturn's largest moon. One of the probes would be a seagoing vessel, designed to sail on Titan's hydrocarbon lakes. Since the surface of Titan is so wildly varied, though, TSSM is also planning to set a hot-air balloon drifting for six months at an altitude of 10 kilometers, recording as it goes.

Proposals for sending a balloon to Titan have existed for a few years now. NASA reports use the term "montgolfiere" to describe the craft, a reference to the hot-air balloon design pioneered by the Montgolfier brothers in 1873. Like these nineteenth-century airships, Titan's balloon would achieve loft by capturing heated gas in a bulbous overhead bag, called an envelope. While the first hot-air balloons kept live fires burning in their gondolas, the heat for Titan's balloon would be generated by an onboard plutonium isotope.

"Hot-air" is a relative term in this case. Titan's mean surface temperature is about -290 Fahrenheit, so a balloon flying over Titan would require only about 1 percent of the heat it would need on Earth. This is one reason a ballooning mission makes sense, though there are others: Titan's slow rotation produces generally calm weather, and a system of trade winds would carry a drifting aircraft all the way around the moon. Just in case the wind doesn't do the trick, the team at TSSM is considering a mechanical propeller to help guide the balloon.

Titan features some of the most diverse terrain to be found anywhere in the solar system. Aside from the massive lakes (the only stable bodies of surface liquid in our system besides Earth's own), Titan also sports deserts, craters, cryovolcanoes and mountains of water ice. A terrestrial rover would be impractical on a world with such eclectic geology. It's hoped that not only could a balloon cover more ground than a wheeled vehicle, but it might even be able to land and scoop a bit of surface material for study.

Most current projections don't put the balloon or the boat on Titan sooner than 2029. An overview of the Titan Saturn System Mission's plans and goals is available online.

In the plans drafted by geologist Ellen Stofan, with funding from NASA, a capsule would splash down in one of these northern lakes — probably Ligeia Mare or Kraken Mare — with a "Lake Lander," known as the Titan Mare Explorer (or TiME for short.) Because solar power is in short supply in Titan's atmosphere, which is full of methane rain and far from the Sun, TiME would use a new kind of nuclear power cell known as the Advanced Stirling Radioisotope Generator (ASRG). The lander wouldn't need sails to zoom along, pushed by Titan's nitrogen winds, but it would have a crow's nest supporting a camera, to gain a better vantage point.

Titan's average temperatures of -292 Fahrenheit are enough to keep those methane/ethane/propane seas liquid. Stofan told Space.Com:

It's very cold, but the technological challenges aren't as big as you might think. Landing in liquid is a lot more forgiving than on land.

Now that Stofan has funding to draw up her plans, she is crafting a proposal for NASA to fund the mission under its Discovery program — and if that gets approved, our nuclear windjammer could explore Titan's seas as soon as 2022. Strohan's report (PDF) is here. [Space.com and The Register]

Report the study authors:

Methane clouds, lakes and most fluvial features on Saturn's moon Titan have been observed in the moist high latitudes, while the tropics have been nearly devoid of convective clouds and have shown an abundance of wind-carved surface features like dunes. The presence of small-scale channels and dry riverbeds near the equator observed by the Huygens probe at latitudes thought incapable of supporting convection (and thus strong rain) has been suggested to be due to geological seepage or other mechanisms not related to precipitation. Here we report the presence of bright, transient, tropospheric clouds in tropical latitudes. We find that the initial pulse of cloud activity generated planetary waves that instigated cloud activity at other latitudes across Titan that had been cloud-free for at least several years. These observations show that convective pulses at one latitude can trigger short-term convection at other latitudes, even those not generally considered capable of supporting convection, and may also explain the presence of methane-carved rivers and channels near the Huygens landing site.

I don't know about you, but I'd love to be caught in a brief methane storm - really gets the air smelling fresh afterwards. Or it would seem like that if you were a Titanian, anyway.

via Nature

The blurry areas (including the dark plains) are spots where we have lower-resolution images of the moon's surface. The stripe of sharper images show the surface of the moon beneath its cloud layer, created via special imaging techniques.

According to Universe Today:

The US Geological Survey Astrogeology Science Center announced the first plain or "planitia" given a name will be designated as Chusuk Planitia. Chusuk was a planet from the Dune series, known for its musical instruments. Chusuk Planitia on Titan is located at 5.0S, 23.5W, and in the picture here is the small, dark area next to the "C" of Chusuk

Chusuk is a minor planet in the Dune series, and in an appendix to that novel, Herbert says it is the "fourth planet of Theta Shalish; the so-called 'Music Planet' noted for the quality of its musical instruments." I'm fairly stumped about why Titan cartographers chose Chusuk. Why not just go for Arrakis?

You can see a complete map of Titan, based on survey pictures taken by the Cassini probe, with all its named features labeled, on this PDF.

Writes New Scientist:

The researchers bombarded the setup with X-rays for up to three days, representing the radiation that Titan would get from the sun over a period of about 7 million years. Afterwards, the still-frozen surface contained some organic compounds, but nothing that could be called the building blocks of life.

But when they heated the samples to room temperature, adenine appeared.

That means Titan's saucepan of proto-life would need a source of extra heat to activate. If there was a warm period in Titan's history, perhaps prompted by volcanic activity or meteoroid impacts, "a primitive life could have had a chance to flourish there", the researchers write.

And Titan is due to be heated up in the next few billion years, when the sun bloats into a red giant star, expanding to the present orbit of Earth, they say.

via New Scientist

This week in San Francisco, researchers at the annual meeting of the American Geophysical Union presented a case for Titan's cryovolcanism, which is today's awesome term of art from the world of geophysics. According to Yahoo News:

Scientists believe methane gas breaks up in the atmosphere and forms clouds that rain methane.

The source of methane remains a mystery. Scientists favoring the volcanic theory say methane eruptions from Titan's interior could explain the moon's smoggy atmosphere.

Data from the spectrometer instrument on Cassini found bright spots on two regions on Titan. In one of the regions, scientists found evidence of ammonia frost that they interpreted as coming from the interior.

You can see one of those dark spots in the image from Titan above.

[via Yahoo News]

Researchers studying data from the European Space Agency’s Huygens probe have reported that Titan’s atmosphere contains a faint electrical field, opening the door to the possibility of lightening strikes on the planet’s surface:

"As of now, lightning activity has not been observed in Titan's atmosphere," said lead author Juan Antonio Morente of the University of Granada in Spain.

But, he said, the signals that have been detected "are an irrefutable proof for the existence of electric activity."

The discovery is a significant one since many biochemists theorize that lightning triggered the reactions necessary for the creation of life on Earth. Since Titan’s atmosphere contains chemicals similar to those in Earth’s prebiotic astmosphere, it increases the possibility that life could form on Titan or in other parts of the universe:

"I look at Titan as a big, frozen, prebiotic casserole," [Jeffrey] Bada [of the Scripps Institution of Oceanography] said, referring to the state before the emergence of life.

"The idea that life could be widespread in the universe, I think, is very credible."

Electricity Found on Saturn Moon—Could It Spark Life? [National Geographic]

This image was taken of the whole lake in 2005, and it's a bit blurry but now you have a sense of the lake's shape. That beach is part of the bulbous right-hand side of the lake. Perfect place for my summer home. When it gets too hot on Earth during those climate changed summers, you'll want to join me on icy Titan to enjoy whiskey-spiked coffee and the fresh aroma of methane rising off those silvery waters. Top image: NASA/JPL/University of Arizona; bottom image - NASA/JPL/Space Science Institute.

Giant Lake Confirmed on Saturn's Moon Titan [via Space.com]

Of course if it has a military application, you know DARPA thought of it first. Back in 2005 the feds funded research into 'XNAV', as they like to call it, to see if it could be used as a backup to GPS in case that system got jammed or went down during a time of war (do these guys ever think about anything other than war?).

But space scientists at PLANS think XNAV is the primary way for future spacecraft to navigate the stars. Using the system, robot spaceships could make their way safely and accurately through interstellar space without human intervention. It might pave the way for ultra-long missions to nearby stars and planets, while the human cargo snores peacefully away in hypersleep.

Source: PLANS conference website

Crowning a moon champion ain't as easy as it seems when Saturn alone has 59 of them. Fortunately the field got smaller when we considered five key points all moons should have on their resumes. It may be hard to stomach having Charon up there — it's questionable that it's even a moon — but someone had to be the goat.

And now, the winners in the individual categories:

BEST FEATURE NAME: Despite tons of creative feature names, Europa wins by a wide margin with Rathmore Chaos. It sounds like a level of Hell from Dante's Inferno, but like most of the outer system, the Chaos is a cold place. In fact it's a jumble of broken up ice that's evidence of the moon's active ice tectonics...and maybe a liquid water ocean below.

POTENTIAL FOR COLONIZATION: Phobos gave Earth's Luna a run for it's money; it's low gravity and proximity to the Red Planet make it worthy of it's full score. But in the end the deck's stacked against the Martian moon — the stated goal for NASA's next generation of manned spaceflight is to return to the moon...to stay.

ACTIVE GEOLOGY: This is a toughy. Uranus' moon Miranda doesn't have active geology, but scientists speculate that the whole moon may have been obliterated by impacts, then reassembled itself. You know, like T-1000 in Terminator 2. Charon, Triton, and Enceladus all look like they've got actively erupting cryovolcanoes of frigid ammonia, water, or liquid nitrogen which is cool, but it knocks Titan down a notch in uniqueness. Jupiter's Io wins for it's self sacrifice though; riddled with volcanoes, the firey moon is literally gutting itself, spewing 1 ton of sulfur dioxide into space every second.

MOVIE/BOOK: The hands-down winner is Earth's Moon, which has been in books and movies since the art forms were invented. It's hardly a fair fight, so the prize goes to Jupiter's Ganymede. The largest moon in the solar system (that's right, bigger than Titan!), it haunts tons of Philip K. Dick's books.

POTENTIAL FOR LIFE: Cryovolcanoes are going off all over the solar system's icy moons, and where there are volcanoes, there's liquid. Most of the liquid is in the form of methane, ammonia, nitrogen, or some other substance that Earth-life wouldn't want to swim in, but who knows what sort of strange aliens could be out there?

That said, Europa's icy shell is made of old-fashioned H2O, and features like Rathmore Chaos look a lot like shifting pack ice here on Earth, which floats on a big ocean of salty water, which in turn contains tons of critters. There's a good chance the same is true on Europa, meaning....

the prize for THE OVERALL AWESOMEST MOON IN THE SOLAR SYSTEM goes to EUROPA!!! Honorable mention to TItan for a strong showing, but it just goes to show...don't mess with the moon with the water oceans under the ice!

Sources: Lunar and Planetary Institute

The Cascadia Astrobiology Institute

Science Direct

WIkipedia

The Nine Planets Solar System Tour

1. Titan is the only moon with a thick, stable atmosphere. It's mostly made of nitrogen, with a decent helping of methane and other hydrocarbons. It's not exactly a breathable atmosphere, but it's still pretty cool. Even better, Titan has Earth-like weather. Wind and rain sweep the surface of Titan, shaping its geography and producing seasonal effects. Some scientists say Titan is a lot like a young Earth, only much colder.

2. Titan has dune seas. As much as 40 percent of the equatorial region might be covered by "sand" dunes hundreds of meters high. They probably aren't made of silicate particles the way Earth sand is. Rather, Titan's sand could be precipitated from the atmosphere. The dunes are sort of like semi-permanent snow drifts.

3. Titan has cryovolcanoes. There are mountains on Titan, along with evidence of volcanic activity. The interior of Titan probably doesn't support the same kind of heat and pressure that we find within the Earth. Instead, Titan's volcanoes might be the result of highly pressurized ice fracturing and spewing liquid water and ammonia into the atmosphere.

4. Titan has liquid features on the surface, like the hydrocarbon lakes pictured in the computer rendering above. Earlier Cassini data found proof of methane lakes in Titan's polar regions. Even more interesting, there might be an entire ocean lying beneath Titan's surface. This leads us to the best reason that Titan is awesome...

5. Titan might be our best bet for finding extraterrestrial life within our solar system. If the subsurface ocean exists, it would be made of liquid water and ammonia and would be warmer than the surface. The chemical makeup of the atmosphere and the active weather and geology have lead some scientists to propose that the conditions on Titan are right for the formation of primitive life. That's exciting. Image by Steven Hobbs via NASA.

Minton, who already created vector maps of the islands in this sea, writes:

I went ahead and digitized the shoreline of the unnamed methane sea . . . It is one of the largest bodies of liquid known to exist on this moon of Saturn. This body of liquid methane, ethane and nitrogen is about the size of Lake Superior.

The orange opacity of Titan's atmosphere makes the moon appear bigger than it actually is - astronomers have since distinguished between permanent cloud cover and surface, and downgraded it from the first- to the second-largest moon in our system, after Jupiter's satellite Ganymede.

Not until the flyby, in 2004, of the Cassini-Huygens mission could scientists confirm the speculation, first ignited by both Voyager missions and then heightened by Hubble observations, that Titan is the only heavenly body (save Earth) to contain large liquid surfaces - or seas, as non-astronomers would call them. For they seem a bit too small to be labelled oceans.

These seas, or lakes, most probably consisting of methane or another hydrocarbon, can be seen on this page of the Jet Propulsion Laboratory in Pasadena.

EVS-Islands [via Strange Maps]

Scientists began to suspect a global ocean when they saw some landmarks on Titan had shifted up to 19 miles between October 2004 and May 2007. The best explanation is a vast ocean, separating the planet's icy crust from its rocky center. The Cassini Space probe will fly within 620 miles of Titan, sample the atmosphere, and take pictures of the site where the Huygens probe landed.

Above, you can see Titan's dunes. Below, there are dunes from an Earth desert. The sand formations are remarkably similar. Images via NASA.