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Titan (Saturn's Largest Moon)

I wish news organisations would stop referring to Hugens as a "Lander"..it is not. 95% of the science from Huygens will come from the decent to the surface on parachutes - it may take as long as 2.5 hours to float down to the surface.

If Huygens survives the landing, and that is a BIG if ... some experiments will be conducted by the "surface science package"

SSP is a suite of laboratory-type sensors for determining the physical properties of the surface at the impact site, and for providing information on the composition of the surface material. The instrument includes a force transducer for measuring the impact deceleration, and sensors to measure the refraction index, temperature, thermal conductivity, heat capacity, speed of sound and dielectric constant of the surface material. It includes an acoustic sounder for sounding the atmosphere's bottom layer and the surface's physical properties before impact. If the Probe lands in a liquid, the sounder will be used to probe the liquid depth. A tilt sensor is included to indicate the Probe's attitude after impact.
 
Cassini Radar Sees Bright Flow-like Feature On Titan

A strikingly bright feature that is consistent with an active geology has been seen in one of Cassini's first radar images of Saturn's moon Titan. There are many possibilities for what it is but one of the leading candidates is that it may be a 'cryovolcanic' flow or 'ice volcano'.

http://saturn.jpl.nasa.gov/news/press-releases-04/20041109-pr-a.cfm
 
Cassini Discovers "Music of the Rings"

From the New Scientist

Original article taken from here

Saturn's magnificent ring system - a huge disc resembling an old gramophone record - turns out to share another property with the LP: it constantly emits a melodic series of musical notes.
The surprising discovery was made by radio and plasma wave detectors on board the Cassini spacecraft as it passed over Saturn's rings during its arrival at the planet in July.

The tones are emitted as radio waves. Don Gurnett of the University of Iowa says his team reduced their frequencies by a factor of five to bring them into the range of human hearing. Gurnett says he was “completely astonished" when he heard the musical notes.

The tones are short, typically lasting between one and three seconds, and unlike the ethereal sliding tones associated with other cosmic processes, every one is quite distinct. The evidence suggests that each tone is produced by the impact of a meteoroid on the icy chunks that make up the rings.
Each hit, Gurnett says, creates a pulse of energy that is focused along the surface of a cone from the point of impact. By estimating the energy involved, he calculates that the impacting objects are about 1 centimetre across - although he cautions that his estimate could be out by as much as a factor of 10.
The findings were reported on Monday at the annual meeting of the American Astronomical Society's Division of Planetary Sciences.

Noisy collisions
Planetary scientists have assumed that meteoroids constantly collide with Saturn’s rings, says Cassini imaging team leader Carolyn Porco, and that process has been suggested as a possible cause of the shifting, spoke-like formations seen in the rings by Voyager 2. But nobody thought it would be possible to detect the impacts so directly.

Cassini's close-up observations have produced a wealth of new information about Saturn's ring system, including complex details in the shapes and spacing of bands that have already revealed signs of three new moons - in addition to the three other moons Cassini had already discovered further out.

The craft's discovery of one of the new moons, and a thin ring near the so-called F-ring, were reported by the International Astronomical Union on Monday.
An ultraviolet spectrometer is also yielding information about variations in the rings' composition, reported Larry Esposito of the University of Colorado. The outer rings are mostly water ice, while the inner A and B rings are far richer in other elements, suggesting a kind of dirty ice.

Finer variations are seen over distances of just a few kilometres. These are so sharp and clear that they suggest the rings are even more dynamic and unstable than had been thought. If the rings had been in their present configuration for more than about 10 million years, their composition would have been thoroughly mixed and would now be uniform, according to dynamical models.
The persistence of the distinct zones suggests that they are variations produced by the break-up of one or more moonlets in the ring region within the past 10 to 100 million years, Esposito says. This rate of change in the rings is about 10 times as rapid as that inferred from their physical features
 
Cassini Mission Status Report

The Cassini spacecraft completed a successful rendezvous with Saturn's moon Titan on Monday, Dec. 13. This was the last pass before the European Space Agency's Huygens probe is sprung loose from Cassini on Christmas Eve (in U.S. time zones). Information gathered during this flyby will provide an opportunity to compare images from Cassini's first close Titan encounter which occurred on Oct. 26.

http://saturn.jpl.nasa.gov/news/press-r ... 4-pr-a.cfm
 
Everything is running to plan:

Saturn's first probe to land 'with a thump or a squelch'

Robin McKie, Science Editor
Sunday December 26, 2004
The Observer

Space engineers sent Europe's Huygens probe sweeping towards Saturn's largest moon, Titan, yesterday. Officials at the Jet Propulsion Laboratory in Pasadena, California, said they had received a signal confirming that the barbecue-sized robot craft had separated from its mother ship, the American-built spaceship Cassini.

Huygens, which is bristling with British-built instruments and detectors, will take 20 days to reach Titan, the only moon in the solar system with an atmosphere. Scientists believe conditions on Titan are similar to those on Earth before life evolved, billions of years ago.

On 14 January, Huygens will enter Titan's thick atmosphere of nitrogen and methane and descend by parachute towards the moon's surface, relaying its data to Cassini above.

Scientists do not know whether the craft will land on a solid, liquid or marshy surface. 'Huygens could land with a thump, a splash or a squelch,' said Professor John Zarnecki, leader of Britain's Huygens team.

One scenario suggests that Titan - whose surface temperature rarely rises above minus 180C - may be covered with lakes, or even seas, of methane or ethane.

The probe - which spins seven times a minute to keep itself stable - is electronically asleep and will only be awoken when on-board instruments detect the tug of Titan's gravitational field.

The craft will have three or four hours to transmit to Cassini before its batteries run out of power. The mother ship will then relay Huygens' data to Earth.

'I've been waiting for this moment, really, for 15 years,' said Zarnecki. 'But for the first time I'm starting to feel nervous.'

David Southwood, of the European Space Agency, said: 'All our hopes and expectations are focused on getting the first in-situ data from a new world we've been dreaming of exploring for decades.'
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Source
 
Another report:

Next stop Titan for space probe

Waiting game after Cassini mission launches its passenger craft towards moon of Saturn 800m miles from Earth

Alok Jha, science correspondent
Monday December 27, 2004
The Guardian

Another Christmas, another multimillion-pound spacecraft making a date to crash-land on another world. Early on Saturday morning a solitary spacecraft 800m miles from Earth ejected a bundle of instruments which will eventually crash into a moon of Saturn. It will be the furthest away that any man-made object has ever landed in over half a century of space exploration.

Unlike last December's ill-fated Beagle 2 mission to Mars, the success of this mission does not depend on the probe landing safely on the surface. Much of its science will be done on its descent through the atmosphere. Any data from the surface will be seen as a bonus.

For the next three weeks, all eyes will be on Huygens, the small probe about the size of a dishwasher that, until last week, had lain dormant inside the £2bn Cassini spacecraft on its seven-year, 2bn-mile journey to Saturn. A pre-programmed sequence of commands successfully activated a spring ejection device and Huygens was pushed away from Cassini at a speed of 30cm a second, spinning at seven revolutions a second. It will now coast towards Saturn's biggest moon, Titan.

Cassini itself is also preparing for a big manoeuvre. Tomorrow, it will steer away from its present trajectory, in which it is following Huygens's crash course, and move to a position where it can listen to Huygens's transmissions next month and relay them back to Earth.

John Zarnecki, a professor of space science at the Open University and a member of the Huygens team who stayed up all night waiting for news on Saturday, said the successful launch was a fantastic Christmas present. "It will now be a very long couple of weeks of waiting before we get any signal to indicate whether the entry and descent has been successful," he said.

"Having worked on this mission for some 15 years, it is a little surreal to think that we are just a couple of weeks away from carrying out scientific investigations on this distant moon that resembles primordial Earth."

Titan is larger than Mercury and is the second largest moon in the solar system after Jupiter's Ganymede.

"Titan is a mysterious place and raises many scientific questions," said Ian Halliday, chief executive of the Particle Physics and Astronomy Research Council, which has contributed £15m on behalf of the UK to the Cassini-Huygens mission. "Its thick atmosphere is mostly nitrogen, but there are also methane and many other organic compounds. Some of them would be signs of life if they were on our planet. Organic compounds form when sunlight destroys methane. If sunlight is constantly destroying methane on Titan, how is methane getting into the atmosphere?"

If all goes to plan, Huygens will get to Titan at 9:07am on January 14. Just as it reaches the outer fringe of the moon's atmosphere, alarm clocks will wake the probe and it will have to prepare to decelerate from 18,000 to 1,400kph in just three minutes as it enters the atmosphere. By the time it reaches the surface, 150 minutes later, it will be travelling at a leisurely 20kph.

In its fall through Titan's atmosphere, Huygens's suite of instruments will measure the physical, chemical and electrical properties around it. The Doppler wind experiment will send radio signals out through the atmosphere to work out what it is made of; and the surface science package, developed by Prof Zarnecki's team, will try to work out what the surface of the planet is made of at the crash site.

Scientists simply don't know what awaits Huygens on Titan's surface. "It's a distinct possibility that I could be the very first scientist to carry out oceanography on an outer planet of the solar system," said Prof Zarnecki. "But equally, the probe could land with a thud on the hard ground or a squelch into a morass of extraterrestrial slime - no one knows for sure."

Whatever happens, the hundreds of scientists from Europe and the US who have been involved in designing, building and monitoring the spacecraft will have to wait until 3pm on January 14 for the first indications of how their experiment has gone, because it takes just over an hour for transmissions from the vicinity of Saturn to reach Earth. By the end of that day, if all has gone well, we might even have our first pictures of Titan's surface.

Once Cassini has finished its part in the mission, it will spend the next four years orbiting Saturn, taking pictures of the planet, mapping its chemical composition.

Huygens will continue to operate until it runs out of power and ends up sitting lifeless on a mysterious moon 800m miles from home.
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Source
 
There is an unusual ridge along Iapetus' equator.

Saturn's Moon Iapetus Shows a Bulging Waistline

01.07.05

Images returned by NASA's Cassini spacecraft cameras during a New Year's Eve flyby of Saturn’s moon Iapetus (eye-APP-eh-tuss) show startling surface features that are fueling heated scientific discussions about their origin.

One of these features is a long narrow ridge that lies almost exactly on the equator of Iapetus, bisects its entire dark hemisphere and reaches 20 kilometers high (12 miles). It extends over 1,300 kilometers (808 miles) from side to side, along its midsection. No other moon in the solar system has such a striking geological feature. In places, the ridge is comprised of mountains. In height, they rival Olympus Mons on Mars, approximately three times the height of Mt. Everest, which is surprising for such a small body as Iapetus. Mars is nearly five times the size of Iapetus.

Images from the flyby are available at http://saturn.jpl.nasa.gov, http://www.nasa.gov/cassini and http://ciclops.org.

Iapetus is a two-toned moon. The leading hemisphere is as dark as a freshly-tarred street, and the white, trailing hemisphere resembles freshly-fallen snow.

The flyby images, which revealed a region of Iapetus never before seen, show feathery-looking black streaks at the boundary between dark and bright hemispheres that indicate dark material has fallen onto Iapetus. Opinions differ as to whether this dark material originated from within or outside Iapetus. The images also show craters near this boundary with bright walls facing towards the pole and dark walls facing towards the equator.

Cassini's next close encounter with Iapetus will occur in September 2007. The resolution of images from that flyby should be 100 times better than the ones currently being analyzed. The hope is that the increased detail may shed light on Iapetus' amazing features and the question of whether it has been volcanically active in the past.

With a diameter of about 1,400 kilometers (890 miles), Iapetus is Saturn's third largest moon. It was discovered by Jean-Dominique Cassini in 1672. It was Cassini, for whom the Cassini-Huygens mission is named, who correctly deduced that one side of Iapetus was dark, while the other was white.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The European Space Agency built and manages the development of the Huygens probe and is in charge of the probe operations. The Italian Space Agency provided the high-gain antenna, much of the radio system and elements of several of Cassini's science instruments. The imaging team is based at the Space Science Institute, Boulder, Colo.


Carolina Martinez (818) 354-9382
NASA's Jet Propulsion Laboratory

Preston Dyches (720) 974-5823
Cassini Imaging Central Laboratory for Operations
Space Science Institute, Boulder, Colo.

2005-005
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Source (with pics): http://www.nasa.gov/mission_pages/cassi ... 10705.html
 
And this extra bit:

Lightning is important. Seething-hot strokes can fuse simple organic molecules into more complicated and interesting things. Some scientists think this is how life began on Earth billions of years ago. A microphone onboard Huygens will listen for thunder (a sign of lightning) and other sounds. For the first time, we'll get to hear what another world sounds like.*
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*italics mine

Excerpted from this: http://www.nasa.gov/mission_pages/cassi ... titan.html article.


I may just have to go on a week long bender.
 
Im on the edge of my seat. (Edwardian corner chair, so its a bit of an odd shape to begin with)
 
sunspot said:
SSP is a suite of laboratory-type sensors for determining the physical properties of the surface at the impact site, and...sensors to measure the refraction index, temperature, thermal conductivity
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That last one's mine - I tested the prototype for the THP (see http://pssri.open.ac.uk/missions/mis-casa1.htm ) at university 14 years ago. I'll be watching out for my old supervisor, Dr John (no-neck) Zarnecki on the live broadcast on Friday night. He's a bit of a meeja hor, despite claiming to hate publicity (he certainly shows up on Sky at Night quite frequently!).

Hope it all goes off according to plan...

Rob
 
Two tone moons

Iapetus was the location of the "star gate" in Arthur C Clark's novel of 2001 (unlike in the film). He imagines aliens have deliberately burnt one side of the moon in order to make a flashing signal to attract our attention.
 
Re: Two tone moons

Austen said:
Iapetus was the location of the "star gate" in Arthur C Clark's novel of 2001 (unlike in the film).
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I thought the exactly same thing when I saw the post about weird surface features.
 
Homo Aves said:
Im on the edge of my seat. (Edwardian corner chair, so its a bit of an odd shape to begin with)
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5 days and counting.....
 
ESA Says Huygens Got a Good Start




Huygens Probe Release

--------------------------------------------------------------------------------

On Christmas Day 2004, the Cassini spacecraft flawlessly released ESA's Huygens probe, passing another challenging milestone for Cassini-Huygens mission. But, with no telemetry data from Huygens, how do we know the separation went well?

At 3:00 CET on 25 December, the critical sequence loaded into the software on board Cassini was executed and, within a few seconds, Huygens was sent on its 20-day trip towards Titan. As data from Cassini confirm, the pyrotechnic devices were fired to release a set of three loaded springs, which gently pushed Huygens away from the mother spacecraft. The probe was expected to be released at a relative velocity of about 0.35 metres per second with a spin rate of about 7.5 revolutions per minute.

Full story
http://saturn.jpl.nasa.gov/news/press-r ... newsID=528
 
Dont forget Friday is the big day for the Huygens decent onto titan, will it make any new and inspiring discoveries....
 
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I know I am hoping that Huygens will provide us with some spectacular information, but I fear in reality that the whole mission will fail beacuse someone didn't write the correct programme to send the info back, or some piece of equipment on the damn thing will fail.
 
Elffriend said:
I know I am hoping that Huygens will provide us with some spectacular information, but I fear in reality that the whole mission will fail beacuse someone didn't write the correct programme to send the info back, or some piece of equipment on the damn thing will fail.
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As long as the first parachute deploys we should get lots of data, remember, it's an atmospheric probe really, if it survives hitting the surface, anything that happens thereafter is a bonus.
 
Why oh why didn't my search find this thread when I was looking for it. I posted stuff on astronomical news :roll:

I am looking forward to this, although the inevitability of disappointment looms greatly :(
 
Elffriend said:
Why oh why didn't my search find this thread when I was looking for it. I posted stuff on astronomical news :roll:

I am looking forward to this, although the inevitability of disappointment looms greatly :(
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I did wonder as i saw a couple of posts regarding this on another thread!
Oh well you have found it now! ;)
 
1033 GMT (5:33 a.m. EST)

SIGNAL FROM HUYGENS! A radio telescope on Earth has detected a faint signal from the descending Huygens spacecraft, confirming the probe is alive, has survived its super-hot entry into the atmosphere and should be carrying out its scientific exploration on the way to the surface of Saturn's moon Titan.

This is just a signal with no actual data included. The data is being relayed to the Cassini orbit and will be played to Earth later today.

Nonetheless, the fact that a signal has been received to verify that Huygens is functioning prompted screams and cheers in mission control.
 
So far so good.

They have `actually` hit the right sattelite....
 
I have been searching for more updates but as far as i can gather there will be an update later this evening.
 
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