Titan (Saturn's Largest Moon)

[OneWingedBird]

But then it looks like a quarry... so I suppose we did in a way.

 

[Mythopoeika]

But then it looks like a quarry... so I suppose we did in a way.

Perfect for filming episodes of Doctor Who.

 

[ramonmercado]

Saturn Moon Titan May Have Ice Floating in Lakes
http://www.space.com/19216-saturn-moon- ... s-ice.html
by SPACE.com Staff Date: 14 January 2013 Time: 08:00 AM ET

This artist's concept envisions what hydrocarbon ice forming on a liquid hydrocarbon sea of Saturn's moon Titan might look like. Image released Jan. 8, 2012.
CREDIT: NASA/JPL-Caltech/USGS

Chunks of hydrocarbon ice may float atop the lakes and seas of Saturn's huge moon Titan, a new study reveals.

The presence of such ice floes in the ethane and methane seas on Titan would make the moon an even more exciting target for astrobiologists, researchers said.

"One of the most intriguing questions about these lakes and seas is whether they might host an exotic form of life," study co-author Jonathan Lunine of Cornell University said in a statement. "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 — Saturn's largest moon, with a diameter of 3,200 miles (5,150 kilometers) — is the only body in our solar system apart from Earth known to host stable bodies of liquid on its surface. While Earth's weather cycle is based on water, Titan's involves hydrocarbons, with liquid ethane and methane falling as rain and pooling in large lakes and seas. [Amazing Photos of Titan]

NASA's Cassini spacecraft has spotted a huge network of these seas in Titan's northern hemisphere, along with a handful in the moon's southern reaches.

Cassini scientists had previously assumed that these seas would not have floating ice, since solid methane is denser than its liquid counterpart and should thus sink. But the new study suggests that things are not so simple.

The researchers created a model investigating how Titan's seas interact with the moon's nitrogen-rich atmosphere, creating pockets of varying composition and temperature.

Lakes on Saturn's moon Titan reflect radio waves in varying ways in this image from NASA's Cassini spacecraft. Image released Jan. 8, 2013.
CREDIT: NASA/JPL-Caltech/ASI/Cornell
e
The team determined that hydrocarbon ice should indeed float in the moon's seas, as long as the temperature is just below methane's freezing point — minus 297 degrees Fahrenheit, or minus 183 degrees Celsius — and the ice is at least 5 percent "air," which is the average composition for young sea ice here on Earth.



This ice may be colorless, perhaps with a reddish-brown tint provided by Titan's atmosphere, researchers said.

"We now know it's possible to get methane-and-ethane-rich ice freezing over on Titan in thin blocks that congeal together as it gets colder — similar to what we see with Arctic sea ice at the onset of winter," lead author Jason Hofgartner, also of Cornell, said in a statement. "We'll want to take these conditions into consideration if we ever decide to explore the Titan surface some day."

Floating sea ice could be a fleeting phenomenon on Titan, if it exists at all. If the temperature drops a few degrees, the ice will begin to sink, researchers said.

Cassini should be able to test the new model out, and soon. Titan's northern spring is underway, meaning lakes and seas in the moon's northern reaches are warming up.

As this happens, ice may rise to the top, creating a surface that appears brighter and more reflective to Cassini's radar instrument. As the area continues to warm, the ice should melt, producing an entirely liquid surface that will look darker to Cassini, researchers said.

"Cassini's extended stay in the Saturn system gives us an unprecedented opportunity to watch the effects of seasonal change at Titan," Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "We'll have an opportunity to see if the theories are right."

The $3.2 billion Cassini mission, a joint effort of NASA, the European Space Agency and the Italian Space Agency, launched in 1997 and arrived at Saturn in 2004. It will continue to observe the ringed planet and its many moons through at least 2017.

 

[ramonmercado]

Astrophile: Icy Titan spawns tropical cyclones
http://www.newscientist.com/article/dn2 ... lones.html
17:42 22 February 2013 by Jeff Hecht

Astrophile is our weekly column on curious cosmic objects, from the solar system to the far reaches of the multiverse

Object: Mini-hurricanes of methane rain
Location: North Pole of Saturn's moon Titan

With a maximum surface temperature of -180 °C, Saturn's icy moon Titan is no tropical paradise, at least by earthly standards. But it may still have tropical cyclones, and at what sounds like the unlikeliest of places – near its north pole.

These mini-hurricanes have never been observed anywhere but Earth. If they exist on Titan, that would add to a growing list of features that the distant moon shares with our planet, from lakes, hills, caves and sand dunes to fog, mist, smoggy haze and rain clouds.

Though cyclones - a large family of storms in which winds spiral inward to a low-pressure zone, such as the eye of a hurricane or tornado – have been glimpsed on Mars and Saturn, a tropical cyclone is a special case that is driven by the heat of evaporation from a warm sea. These storms involve a lot of rain as well as gale-force winds, and have not been glimpsed anywhere but Earth.

As Titan is the only body in the solar system apart from Earth known to have liquid on its surface and, therefore, rain (Titan is so cold that its rain is in the form of liquid methane, not water), Tetsuya Tokano of the University of Cologne in Germany decided to calculate what it would take for Titan to have its own mini-hurricanes.

Methane seas

The first thing that would be required, he says, is the right blend of hydrocarbons in the moon's lakes and seas. "We know ethane is present, and methane probably is," he says. The methane is crucial because it evaporates much more readily, and could deliver the heat needed to drive the storm.

Assuming the methane fraction is large enough, Tokano calculated the heat it would carry and how that would be converted into kinetic energy to power a storm. He reckons that the resulting storm would not be as powerful as hurricanes or typhoons on Earth, but that they could produce surface winds of up to 20 metres per second (72 kilometres per hour). That's 10 times the average wind velocity on Titan: on Earth, it's equivalent to the wind speeds of a midsize tropical storm – and two-thirds those needed for a full-scale hurricane.

Tokano also looked at where these could storms could form – and discovered that the 1200-kilometer-long Kraken Mare, and the smaller Ligeia and Punga mares, are the only seas on Titan large enough to support the growth of a tropical cyclone. All three are situated near Titan's North Pole, making a contrast to the tropical cyclones on Earth.

As on Earth, however, any mini-hurricanes on Titan would be seasonal. Tokano says the storms could form in Titan's northern summer, lasting up to 10 days and reaching hundreds of kilometres in diameter, limited by the size of the lakes.

Spectacular storm

It's now spring on northern Titan, and solar warming of the north pole should make the storms possible from 2015 to 2021. (Because Titan is so much further away from the sun than Earth, its year – and therefore its seasons - are much, much longer.)

That means that when mini-hurricane season next returns to Titan, the Cassini spacecraft, which started orbiting it in 2004, will still be watching. The craft's orbit gives it a better view of Titan's poles than terrestrial telescopes, and its mission is scheduled to continue until 2017.

"It would be spectacular to see this kind of storm over Kraken Mare," says Elizabeth Turtle of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "This gives us a specific type of storm to look for."

Failure to spot a storm during this period would not tell us much, however, says Tokano, as any of a number of factors might cause Cassini to miss it, or it might just be a slow season.

Because of its similarities to Earth, Titan looks like a good place to hunt for extra-terrestrial life. Though Tokano wouldn't be drawn on how tropical cyclones might feed into this picture, one thing is clear: the frigid moon is certainly living up to its reputation as one of the most intriguing places in our solar system.

Journal reference: Icarus, doi.org/kkx

 

[ramonmercado]

NASA considers sending quadcopter drone to look for life on Titan

While one NASA probe whizzes by Saturn’s moon Titan on Thursday to analyze its atmosphere, the American space agency is also considering a plan to send a quadcopter drone capable of searching for life.

The ambitious idea was outlined by Larry Matthies, a research scientist and supervisor at NASA’s Jet Propulsion Lab in California, and involves a drone that would be capable of flying out of a lander or balloon. The drone would explore the moon’s landscape and seas, collect samples, and return to the “mothership” in order to recharge its batteries and submit whatever it collects for analysis.

If successful, the new plan could drastically change the way humans explore space. Current rovers on Mars are akin to moving laboratories, but their grounded nature means they can be rather limited when it comes to exploring terrain. The 22-pound drone conceived by Matthies would eliminate that barrier with flight capability, allegedly at much lower costs than other options.

As quoted by Gizmodo, he described the plan as follows:

“We propose a mission study of a small (< 10 kg) rotorcraft that can deploy from a balloon or lander to acquire close-up, high resolution imagery and mapping data of the surface, land at multiple locations to acquire microscopic imagery and samples of solid and liquid material, return the samples to the mothership for analysis, and recharge from an RTG on the mothership to enable multiple sorties.” ...
http://rt.com/usa/167124-nasa-send-quad ... one-titan/

 

[eburacum]

Mystery object in lake on Saturn's moon Titan intrigues scie

Mystery object in lake on Saturn's moon Titan intrigues scientists

http://www.theguardian.com/science/2014 ... tists-nasa

Nasa's Cassini probe took image last year as it passed by planet's largest moon – nothing seen when other images taken


Scientists are investigating a mystery object that appeared for a moment and then vanished again from a giant lake on Titan, the largest moon of Saturn.

They spotted the object in an image taken by Nasa's Cassini probe as it swung around the alien moon last year more than a billion kilometres from Earth. Pictures taken of the same spot saw nothing before or some days later.

Little more than a white blob on a grainy image of Titan's northern hemisphere, the sighting may be a huge iceberg that broke free of the shoreline, an effect of rising bubbles, or waves rolling across the normally placid lake's surface, scientists say.

Astronomers have named the blob the "magic island" until they have a better idea what they are looking at. "We can't be sure what it is yet because we only have the one image, but it's not something you would normally see on Titan," said Jason Hofgartner, a planetary scientist at Cornell University in New York. "It is not something that has been there permanently."

Titan is one of the most extraordinary places in the solar system. The land is strewn with hydrocarbon dunes that rise above lakes fed by rivers of liquid methane and ethane. The atmosphere is so thick, and the gravity so weak, that a human could strap on wings and flap into the air. That air is laced with lethal hydrogen cyanide.

The largest moon of Saturn – there are more than 60 smaller ones – is the only place beyond Earth known to have stable liquids on its surface and rain falling from its skies. Spacecraft have mapped out scores of lakes there. The three biggest are named after mythological beasts, the Kraken, Ligeia and Punga, and are large enough to qualify as seas, or mares.

The US team made their curious discovery while poring over radar images of Ligeia mare, a 150m-deep sea that stretches for hundreds of kilometres in either direction, in Titan's northern hemisphere. Among the snapshots taken during fly-bys in 2007, 2009 and 2013 was one with the strange white feature, around six miles off the mountainous southern shore.
'Magic island' found on Saturn moon Titan NASA handout photo dated 26/04/07 of the area in Titan's Ligeia mare before the object was seen (top) and 10/07/13 of the 'magic island'. Photograph: JPL-Caltech/ASI/Cornell/NASA/PA

Roughly 12 miles long and six miles wide, the bright spot appears in an image dated 10 July 2013 but is missing from pictures of the same spot taken previously, and about two weeks later, on 26 July. Hofgartner said the team has ruled out any errors in the radar imaging equipment that could give rise to the blob.

Through a process of elimination, the scientists whittled the number of potential explanations down to four. It could be one or more icebergs floating around, or some material in suspension beneath the surface. But Cassini's radar might have picked up a rush of bubbles coming from the depths of the sea, or captured the first signs of deep sea waves on Titan.

Last year's Cassini fly-by found that Ligeia mare, Titan's second largest lake, was as smooth as glass. The almost eerily-tranquil expanse of liquid methane and ethane had no waves or surface ripples larger than one millimetre. The profound stillness may be due to the wind on Titan being so feeble. But that could be about to change.

Titan's orbital path and tilted axis make for seasons that last for seven Earth years. The northern hemisphere is gently warming now, as spring gives way to summer which arrives in earnest in 2017. Warmer weather brings stronger winds, and stronger winds bring waves.

"This may be waves picking up. The sun is shining brighter, and that energy can be powering the winds. All you would need is a light breeze, around half a metre per second," said Hofgartner, whose study appeared in the journal Nature Geoscience.

But the wind on Titan may never be strong enough to stir truly impressive waves. "If you had a large enough surfboard, you could certainly float there, but I don't think you'd really get the waves you'd want," Hofgartner said. The hydrocarbon seas, he added, are a chilly -180C.

If waves are the cause of the curious white blob, then Cassini spotted them before they had spread more widely across the Titan sea. Follow-up images in the next few months are expected to shed more light on the mystery.

In March, some of the researchers who worked with Hofgartner reported what may have been glimpses of tiny waves on another Titan sea called Punga mare. Instruments aboard Cassini found that sunlight reflecting off the sea was brighter than expected in places, an effect that could be caused by waves lapping at the shore.

Nasa has toyed with the idea of sending a boat to sail on the seas of Titan, but the proposal lost out to a mission to Mars. But there are still hopes to explore the moon with two other Nasa missions. One would fly a balloon on Titan and release a drone to map the surface. The other aims to drop a submarine into the largest of Titan's seas, the 300m-deep Kraken mare.

 

[rynner2]

The BBC report on this is here:
http://www.bbc.co.uk/news/science-environment-27957274

Is this the first mention of the World Cup in a planetary science report?

Speaking to the BBC from Rio de Janeiro, where he has been following England at the World Cup, Prof Zarnecki referred to the waves he could see crashing on to Copacabana Beach, and said: "I'd love to think that this paper represents the first positive indication of a similar phenomenon on Titan."

Titan is tidally locked with Saturn, which also means it has no tides in its bodies of liquid, so tides can't be the explanation for the Magic Island.

 

[amester]

The "Thus Sprach Zarathustra" theme is going through my mind

 

[ramonmercado]

The BBC report on this is here:
http://www.bbc.co.uk/news/science-environment-27957274

Is this the first mention of the World Cup in a planetary science report?

Speaking to the BBC from Rio de Janeiro, where he has been following England at the World Cup, Prof Zarnecki referred to the waves he could see crashing on to Copacabana Beach, and said: "I'd love to think that this paper represents the first positive indication of a similar phenomenon on Titan."

Titan is tidally locked with Saturn, which also means it has no tides in its bodies of liquid, so tides can't be the explanation for the Magic Island.

Maybe MH370 landed on it.

 

[OneWingedBird]

Titan is tidally locked with Saturn, which also means it has no tides in its bodies of liquid, so tides can't be the explanation for the Magic Island.

The orbit is slightly eliptical though with a period of 15ish days - I wonder if that would be enough to change the ocean level according to where in the elipse Titan is?

The timescale they're discussing seems congruent.

 

[rynner2]

Titan is tidally locked with Saturn, which also means it has no tides in its bodies of liquid, so tides can't be the explanation for the Magic Island.

The orbit is slightly eliptical though with a period of 15ish days - I wonder if that would be enough to change the ocean level according to where in the elipse Titan is?

The timescale they're discussing seems congruent.

Titan's seas are land locked. You only get tides in such a body if any tide-raising forces resonate with the 'sloshing frequency' of the body. Then you get high tide at one end when it's low tide at the other. But I'll leave it to the experts to check that out! 8)

 

[eburacum]

Another source of tides is the influence of other moons as they pass. These will be very temporary and short tides, if they occur at all. Just like the appearance of the Magic Island itself.

 

[rynner2]

Another source of tides is the influence of other moons as they pass. These will be very temporary and short tides, if they occur at all. Just like the appearance of the Magic Island itself.

Again I'll leave the calculations to the experts, but my gut feeling on this idea is that the moons are so far apart, and relatively small, that any tide raised would probably be immeasurably small.

 

[ramonmercado]

NASA developing submarine to research Titan’s oceans

An artist's imagination of hydrocarbon pools, icy and rocky terrain on the surface of Saturn's largest moon Titan. Image credit: Steven Hobbs (Brisbane, Queensland, Australia).

Researchers are currently working with $100,000 worth of government funding to try and design a submarine that might someday be able to explore the depths of the sea on Saturn’s moon, Titan.

NASA announced in early June that it selected a proposed space submarine project as one of the 12 concepts that researchers will have nine months-to-one year to strive towards with the help of a hefty grant; at the end of that trial period, the agency may elect to hand over another $500,000 to any projects from the first round of prototyping deemed worthy of participating in a two-year, Phase II stage.

Steven Oleson of NASA’s Glenn Research Center in Cleveland, Ohio wrote in his initial proposal for the Titan submarine that the moon of Saturn provides scientists with an unique template for space tests, but has up until now hardly been fully explored.

“Titan is unique in the outer solar system in that it is the only one of the bodies outside the Earth with liquid lakes and seas on its surface. The Titanian seas, however, are not composed of water, like Earth’s seas, but are seas of liquid hydrocarbons,” Oleson wrote. “What lies beneath the surface of Titan’s seas? We propose to develop a conceptual design of a submersible autonomous vehicle (submarine) to explore extraterrestrial seas.” ...

http://rt.com/usa/186432-nasa-develops-submarine/

 

[ramonmercado]

Surprise! Methane Ice Cloud Floats High Above Saturn's Moon Titan

NASA's Cassini probe imaged a cloud in the stratosphere over the north pole of Saturn's moon Titan during a flyby in December 2006.
Credit: NASA/JPL/University of Arizona/LPGNantes

In a celestial surprise, NASA's Cassini spacecraft has identified a cloud of methane ice high in the stratosphere of Saturn's huge moon Titan.

"The idea that methane clouds could form this high on Titan is completely new," study lead author Carrie Anderson, a Cassini participating scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. "Nobody considered that possible before."

Anderson and her colleagues spotted the methane cloud hovering over Titan's north pole in images taken by Cassini in December 2006, when it was winter in the moon's northern hemisphere. (The north is now shifting from spring into summer.) ...
http://www.space.com/27558-saturn-moon- ... cloud.html

 

[ramonmercado]

Two new "magic islands" have joined one reported last year on Saturn's giant moon Titan, Cassini spacecraft observations showed on Monday. The features add to a puzzling vanishing act playing out on the frozen world's seas.

Since Cassini first arrived at Saturn in 2004, its photos of Titan have revealed numerous seas, lakes, and rivers on the giant moon's frozen surface. This summer, images showed a mysterious feature in one sea—the first "magic island"—that appeared glinting on a lake's surface and then quickly vanished. (Related: "Waves Discovered on Saturn's Moon, Titan?")

The find raised speculation that scientists had captured views of waves splashing within the otherwise mirror-smooth liquid methane seas on the moon. Or else it was a fluke. ...

http://news.nationalgeographic.com/news ... e-science/

 

[ramonmercado]

A new type of methane-based, oxygen-free life form that can metabolize and reproduce similar to life on Earth has been modeled by a team of Cornell University researchers.

Taking a simultaneously imaginative and rigidly scientific view, chemical engineers and astronomers offer a template for life that could thrive in a harsh, cold world - specifically Titan, the giant moon of Saturn. A planetary body awash with seas not of water, but of liquid methane, Titan could harbor methane-based, oxygen-free cells.

Their theorized cell membrane, composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero, is published in Science Advances, Feb. 27. The work is led by chemical molecular dynamics expert Paulette Clancy and first author James Stevenson, a graduate student in chemical engineering. The paper's co-author is Jonathan Lunine, director for Cornell's Center for Radiophysics and Space Research. ...

http://phys.org/news/2015-02-life-saturn-moon-titan.html

 

[Bigphoot2]

Is Titan submarine the most daring space mission yet?
By Paul Rincon Science editor, BBC News website, The Woodlands

The submersible could extract cores from the seabed to unlock a rich climatic history
Dropping a robotic lander on to the surface of a comet was arguably one of the most audacious space achievements of recent times.
But one concept mission being studied by the US space agency could top even that.
Scientists are proposing to send a robot submarine to the oily seas of Saturn's moon Titan. The seas are filled not with water, but with hydrocarbons like methane and ethane.
These compounds exist in their liquid state on the moon, where the temperature averages -180C.

http://www.bbc.co.uk/news/science-environment-31854559

 

[ramonmercado]

Saturn's moon Titan is home to seas and lakes filled with liquid hydrocarbons, but what forms the depressions on the surface? A new study using data from the joint NASA and the European Space Agency (ESA) Cassini mission suggests the moon's surface dissolves in a process that's similar to the creation of sinkholes on Earth.

Apart from Earth, Titan is the only body in the solar system known to possess surface lakes and seas, which have been observed by the Cassini spacecraft. But at Titan's frigid surface temperatures -- roughly minus 292 degrees Fahrenheit (minus 180 degrees Celsius) -- liquid methane and ethane, rather than water, dominate Titan's hydrocarbon equivalent of Earth’s water.

Cassini has identified two forms of methane- and ethane-filled depressions that create distinctive features near Titan's poles. There are vast seas several hundred miles (or kilometers) across and up to several hundred feet (or meters) deep, fed by branching, river-like channels. There also are numerous smaller, shallower lakes, with rounded edges and steep walls that are generally found in flat areas. Cassini also has observed many empty depressions.

The lakes are generally not associated with rivers, and are thought to fill up by rainfall and liquids feeding them from underground. Some of the lakes fill and dry out again during the 30-year seasonal cycle on Saturn and Titan. But exactly how the depressions hosting the lakes came about in the first place is poorly understood.

Recently a team of scientists turned to our home planet for the answer. They discovered that Titan's lakes are reminiscent of what are known as karstic landforms on Earth. These are terrestrial landscapes that result from erosion of dissolvable rocks, such as limestone and gypsum, in groundwater and rainfall percolating through rocks. Over time, this leads to features like sinkholes and caves in humid climates, and salt-pans where the climate is more arid. ...

http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20150619/

 

[ramonmercado]

NASA has just funded seven far-out space-exploration concepts, including a submarine that would explore the hydrocarbon seas of Saturn's huge moon Titan, an origami energy reflector and rapid space transit with an electric sail.

All of the proposals, including the one for the Titan submarine, have been awarded funding under Phase II of the NASA Innovative Advanced Concepts program, or NIAC.

Phase II grants, which are worth up to $500,000, allow scientists to continue working on bold ideas that received Phase I NIAC funding. The grants are intended to encourage development of potentially transformative space technology, and offer the resources to test the feasibility and intricacies of brand-new ideas. [Incredible Technology: Space Travel and Exploration]

http://www.space.com/29953-titan-submarine-nasa-niac-proposals.html?cmpid=514648

 

[ramonmercado]

For the next six months, NASA's Saturn-orbiting Cassini spacecraft will get its final look at two icy moons — one famous and one not so well-known. It will fly by the erupting moon Enceladus three times, checking out its plumes in the best detail to date. And it will take one last look at the moon Dione (pronounced die-OWN-ee), which may have eruptions as well.

PHOTOS: Cassini's 10th Year: Recent Saturn Mind Blowers

Why are icy moons so interesting to astronomers? One reason is they represent some of the best chances of finding life in our solar system. Many of these icy moons are believed to host global oceans underneath. Warmed by gravitational interactions with massive Saturn, there could be microbes floating under the surface just waiting for us to examine. [Latest Saturn Photos from NASA's Cassini]

The long last look at Dione will take place Aug. 17, when Cassini will do gravitational measurements to learn more about its interior and icy shell. "There are intriguing hints that perhaps there's something similar going on on Dione that we might have on Enceladus, but we haven't found the equivalent of a smoking gun," Linda Spilker, the Cassini project scientist at NASA's Jet Propulsion Laboratory, told Discovery News.

http://www.space.com/30105-cassini-final-flybys-saturn-moons.html?cmpid=514648

 

[hunck]

Some fantastic pictures in those links. I'd not realised Cassini has been orbiting the Saturn system for 11 years.

 

[ramonmercado]

The Cassini spacecraft will make one last close flyby of Saturn's pockmarked moon Dione today (Aug. 17), in search of direct evidence that the moon is geologically alive and active.

Cassini, a collaboration between NASA, the European Space Agency and the Italian Space Agency, has been studying the Saturn system since 2004, and its grand mission will come to a close in 2017, after the spacecraft makes a series of dives through the space between the planet and its rings. On Monday, Cassini will make its fifth close flyby of Dione, coming to within 295 miles (474 kilometers) of the moon's surface, at approximately 2:33 p.m. EDT (6:33 GMT).

"Dione has been an enigma, giving hints of active geologic processes, including a transient atmosphere and evidence of ice volcanoes — but we've never found the smoking gun," Bonnie Buratti, a Cassini science team member at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement from NASA. "The fifth flyby of Dione will be our last chance." [Saturn Quiz: Do You Really Know the Ringed Planet?]

http://www.space.com/30264-cassini-final-flyby-saturn-moon-dione.html?cmpid=514648

 

[Mythopoeika]

Only 30 miles should get them amazing photos.

 

[ramonmercado]

New observations made near the south pole of Titan by NASA’s Cassini spacecraft add to the evidence that winter comes in like a lion on this moon of Saturn.

Scientists have detected a monstrous new cloud of frozen compounds in the moon’s low- to mid-stratosphere – a stable atmospheric region above the troposphere, or active weather layer.

Cassini’s camera had already imaged an impressive cloud hovering over Titan’s south pole at an altitude of about 186 miles (300 kilometers). However, that cloud, first seen in 2012, turned out to be just the tip of the iceberg. A much more massive ice cloud system has now been found lower in the stratosphere, peaking at an altitude of about 124 miles (200 kilometers).

This 2012 close-up offers an early snapshot of the changes taking place at Titan’s south pole. Cassini’s camera spotted this impressive cloud hovering at an altitude of about 186 miles (300 kilometers). Now, Cassini’s thermal infrared instrument has now detected a massive ice cloud below it. Image Credit: NASA/JPL-Caltech/Space Science Institute

The new cloud was detected by Cassini’s infrared instrument – the Composite Infrared Spectrometer, or CIRS – which obtains profiles of the atmosphere at invisible thermal wavelengths. The cloud has a low density, similar to Earth’s fog but likely flat on top.

For the past few years, Cassini has been catching glimpses of the transition from fall to winter at Titan’s south pole – the first time any spacecraft has seen the onset of a Titan winter. Because each Titan season lasts about 7-1/2 years on Earth’s calendar, the south pole will still be enveloped in winter when the Cassini mission ends in 2017.


Read more at http://www.deepstuff.org/nasas-cass...itans-south-polar-region/#5vLv2I5lKiv8omkp.99

 

[ramonmercado]

Surfing onTitan would be best in summer

Space is mostly vast and empty. So whenever we notice something like ripples on a lake, on the frozen moon of a gas giant, we take notice.

At a meeting of the American Geophysical Union in San Francisco this week, it was reported that Cassini images of Saturn's moon Titan showed light being reflected from the Ligeia Mare, a frigid sea of hydrocarbons on that moon. Subsequent images showed the same phenomenon on two other seas of Titan, as well. These are thought to be waves, the first waves detected anywhere other than Earth, and suggest that Titan has more geophysical activity than previously thought.

Surfers on Earth, known for seeking out remote and secretive locations, shouldn't get too excited. According to mathematical modelling and radar imagery, these waves are only 1.5 cm (0.6 inches) tall, and they're moving only 0.7 metres (2.3 feet) per second. Plus, they're on a sea of liquid hydrocarbons—mostly methane—that is a frigid -180 degrees Celsius (-292 F.)

Planetary scientists are taking note, though, because these waves show that Titan has an active environment, rather than just being a moon frozen in time. It's thought that the change in seasons on Titan is responsible for these waves, as Titan begins its 7 year summer. Processes related to the changing seasons on Titan have created winds, which have cause these ripples.



Read more at: http://phys.org/news/2016-03-surfing-ontitan-summer.html#jCp

 

[OneWingedBird]

Was having a look around the London Science Museum this morning, they have a lieft size model of the Huygens probe on display.

Can't say that I'd ever given much thought about the size of it before, it's surprisingly dinky, a disk shape perhaps 4 foot diameter and a couple of feet high.

 

[ramonmercado]

Sirens of Titan: Flying Aerobot Drone Could Soar Over Saturn Moon

As the long-running Cassini mission enters its last year at Saturn, NASA is moving forward with an early-stage technology study to send a drone to its moon Titan.

The agency awarded a Small Business Innovation Research (SBIR) Phase 1 contract for Global Aerospace Corp. and Northrop Grumman Aerospace Systems to create a vehicle known as the Titan Winged Aerobot built to explore Saturn's largest moon and prepare a prototype for testing on Earth. SBIR Phase 1 contracts last six months and are worth up to $125,000,according to NASA.

"Titan is a cold, harsh environment that poses many technical challenges for any lighter-than-air exploration platform," said Benjamin Goldman, principal investigator of the Phase I effort, in a statement from Global. [How Humans Could Live on Titan (Infographic)]

The new Titan robot will include several design elements to let it cope with that environment, he added in the statement. This would include excellent "lift" generation (the ability to soar using Titan's dense atmosphere), maneuverability and the ability to withstand Titan's atmospheric pressure.

Titan is the only known solar system moon to have a substantial atmosphere and a liquid cycle (including hydrocarbon lakes on its surface), which has led some scientists to compare it to an early Earth. It also could host methane-based life despite its harsh temperatures (minus 300 Fahrenheit, or minus 184 Celsius, at the surface) and lack of water, which earthly creatures require. ...

http://www.space.com/33412-nasa-aer...aign=socialtwitterspc&cmpid=social_spc_514648

 

[Bigphoot2]

Meanwhile on Titan...

Cassini Finds Flooded Canyons on Titan

NASA's Cassini spacecraft pinged the surface of Titan with microwaves, finding that some channels are deep, steep-sided canyons filled with liquid hydrocarbons. One such feature is Vid Flumina, the branching network of narrow lines in the upper-left quadrant of the image.
Credits: NASA/JPL-Caltech/ASI
Original image and caption

The canyons of Vid Flumina are seen in this view from Cassini's radar mapper.
Credits: NASA/JPL-Caltech/ASI
Original image and caption
NASA's Cassini spacecraft has found deep, steep-sided canyons on Saturn's moon Titan that are flooded with liquid hydrocarbons. The finding represents the first direct evidence of the presence of liquid-filled channels on Titan, as well as the first observation of canyons hundreds of meters deep.



A new paper in the journal Geophysical Research Letters describes how scientists analyzed Cassini data from a close pass the spacecraft made over Titan in May 2013. During the flyby, Cassini's radar instrument focused on channels that branch out from the large, northern sea Ligeia Mare.



The Cassini observations reveal that the channels -- in particular, a network of them named Vid Flumina -- are narrow canyons, generally less than half a mile (a bit less than a kilometer) wide, with slopes steeper than 40 degrees. The canyons also are quite deep -- those measured are 790 to 1,870 feet (240 to 570 meters) from top to bottom.



The branching channels appear dark in radar images, much like Titan's methane-rich seas. This suggested to scientists that the channels might also be filled with liquid, but a direct detection had not been made until now. Previously it wasn't clear if the dark material was liquid or merely saturated sediment -- which at Titan's frigid temperatures would be made of ice, not rock.



Cassini's radar is often used as an imager, providing a window to peer through the dense haze that surrounds Titan to reveal the surface below. But during this pass, the radar was used as an altimeter, sending pings of radio waves to the moon's surface to measure the height of features there. The researchers combined the altimetry data with previous radar images of the region to make their discovery.



Key to understanding the nature of the channels was the way Cassini's radar signal reflected off the bottoms of the features. The radar instrument observed a glint, indicating an extremely smooth surface like that observed from Titan's hydrocarbon seas. The timing of the radar echoes, as they bounced off the canyons' edges and floors, provided a direct measure of their depths.



The presence of such deep cuts in the landscape indicates that whatever process created them was active for a long time or eroded down much faster than other areas on Titan’s surface. The researchers' proposed scenarios include uplift of the terrain and changes in sea level, or perhaps both.



"It's likely that a combination of these forces contributed to the formation of the deep canyons, but at present it's not clear to what degree each was involved. What is clear is that any description of Titan's geological evolution needs to be able to explain how the canyons got there," said Valerio Poggiali of the University of Rome, a Cassini radar team associate and lead author of the study.



Earthly examples of both of these types of canyon-carving processes are found along the Colorado River in Arizona. An example of uplift powering erosion is the Grand Canyon, where the terrain's rising altitude caused the river to cut deeply downward into the landscape over the course of several million years. For canyon formation driven by variations in water level, look to Lake Powell. When the water level in the reservoir drops, it increases the river's rate of erosion.



"Earth is warm and rocky, with rivers of water, while Titan is cold and icy, with rivers of methane. And yet it's remarkable that we find such similar features on both worlds," said Alex Hayes, a Cassini radar team associate at Cornell University, Ithaca, New York, and a co-author of the study.



While the altimeter data also showed that the liquid in some of the canyons around Ligeia Mare is at sea level -- the same altitude as the liquid in the sea itself -- in others it sits tens to hundreds of feet (tens of meters) higher in elevation. The researchers interpret the latter to be tributaries that drain into the main channels below.



Future work will extend the methods used in this study to all other channels Cassini's radar altimeter has observed on Titan. The researchers expect their continued work to produce a more comprehensive understanding of forces that have shaped the Saturnian moon's landscape.



The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the US and several European countries.



More information about Cassini:



http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

https://www.nasa.gov/feature/jpl/cassini-finds-flooded-canyons-on-titan

 

[Bigphoot2]

NASA Scientists Find 'Impossible' Cloud on Titan -- Again

The hazy globe of Titan hangs in front of Saturn and its rings in this natural color view from NASA's Cassini spacecraft. Image credit: NASA/JPL-Caltech/Space Science Institute
› Full image and caption
The puzzling appearance of an ice cloud seemingly out of thin air has prompted NASA scientists to suggest that a different process than previously thought -- possibly similar to one seen over Earth's poles -- could be forming clouds on Saturn's moon Titan.

Located in Titan's stratosphere, the cloud is made of a compound of carbon and nitrogen known as dicyanoacetylene (C4N2), an ingredient in the chemical cocktail that colors the giant moon's hazy, brownish-orange atmosphere.

Decades ago, the infrared instrument on NASA's Voyager 1 spacecraft spotted an ice cloud just like this one on Titan. What has puzzled scientists ever since is this: they detected less than 1 percent of the dicyanoacetylene gas needed for the cloud to condense.

Recent observations from NASA's Cassini mission yielded a similar result. Using Cassini's composite infrared spectrometer, or CIRS -- which can identify the spectral fingerprints of individual chemicals in the atmospheric brew -- researchers found a large, high-altitude cloud made of the same frozen chemical. Yet, just as Voyager found, when it comes to the vapor form of this chemical, CIRS reported that Titan's stratosphere is as dry as a desert.

"The appearance of this ice cloud goes against everything we know about the way clouds form on Titan," said Carrie Anderson, a CIRS co-investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study.

The typical process for forming clouds involves condensation. On Earth, we're familiar with the cycle of evaporation and condensation of water. The same kind of cycle takes place in Titan's troposphere -- the weather-forming layer of Titan's atmosphere -- but with methane instead of water.

A different condensation process takes place in the stratosphere -- the region above the troposphere -- at Titan's north and south winter poles. In this case, layers of clouds condense as the global circulation pattern forces warm gases downward at the pole. The gases then condense as they sink through cooler and cooler layers of the polar stratosphere.

Either way, a cloud forms when the air temperature and pressure are favorable for the vapor to condense into ice. The vapor and the ice reach a balance point -- an equilibrium -- that is determined by the air temperature and pressure. Because of this equilibrium, scientists can calculate the amount of vapor where ice is present.

"For clouds that condense, this equilibrium is mandatory, like the law of gravity," said Robert Samuelson, an emeritus scientist at Goddard and a co-author of the paper.

But the numbers don't compute for the cloud made from dicyanoacetylene. The scientists determined that they would need at least 100 times more vapor to form an ice cloud where the cloud top was observed by Cassini's CIRS.

One explanation suggested early on was that the vapor might be present, but Voyager's instrument wasn't sensitive enough in the critical wavelength range needed to detect it. But when CIRS also didn't find the vapor, Anderson and her Goddard and Caltech colleagues proposed an altogether different explanation. Instead of the cloud forming by condensation, they think the C4N2 ice forms because of reactions taking place on other kinds of ice particles. The researchers call this "solid-state chemistry," because the reactions involve the ice, or solid, form of the chemical.

The first step in the proposed process is the formation of ice particles made from the related chemical cyanoacetylene (HC3N). As these tiny bits of ice move downward through Titan's stratosphere, they get coated by hydrogen cyanide (HCN). At this stage, the ice particle has a core and a shell comprised of two different chemicals. Occasionally, a photon of ultraviolet light tunnels into the frozen shell and triggers a series of chemical reactions in the ice. These reactions could begin either in the core or within the shell. Both pathways can yield dicyanoacteylene ice and hydrogen as products.

The researchers got the idea of solid-state chemistry from the formation of clouds involved in ozone depletion high above Earth's poles. Although Earth's stratosphere has scant moisture, wispy nacreous clouds (also called polar stratospheric clouds) can form under the right conditions. In these clouds, chlorine-bearing chemicals that have entered the atmosphere as pollution stick to crystals of water ice, resulting in chemical reactions that release ozone-destroying chlorine molecules.

"It's very exciting to think that we may have found examples of similar solid-state chemical processes on both Titan and Earth," said Anderson.

The researchers suggest that, on Titan, the reactions occur inside the ice particles, sequestered from the atmosphere. In that case, dicyanoacetylene ice wouldn't make direct contact with the atmosphere, which would explain why the ice and the vapor forms are not in the expected equilibrium.

"The compositions of the polar stratospheres of Titan and Earth could not differ more," said Michael Flasar, CIRS principal investigator at Goddard. "It is amazing to see how well the underlying physics of both atmospheres has led to analogous cloud chemistry."

The findings are published in the journal Geophysical Research Letters.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. The CIRS instrument was built by Goddard.

For more information about Cassini, visit:
http://www.nasa.gov/cassini
http://saturn.jpl.nasa.gov

http://www.jpl.nasa.gov/news/news.php?feature=6625