LittleMilkJug

Huygens lands on Saturn moon
By Michael Coren
CNN
Friday, January 14, 2005 Posted: 9:23 AM EST (1423 GMT)



TITAN: Largest Saturnian moon. May harbor organic compounds similar to those predating life on Earth. Temperature is minus 292 degrees F (180 C).

HUYGENS PROBE: Spacecraft is 8.9 feet in diameter and 703 pounds (317 kg). Was released from Cassini on December 24 and enter Titan's atmosphere on January 14.

It will take two hours for Huygens to parachute to the surface.

After touchdown the probe will sample Titan's atmosphere, measure its wind and rain, listen for alien sounds and, when the clouds part, start taking pictures.

Source: NASA




(CNN) -- Huygens has arrived.

The probe landed on the surface of Saturn's moon Titan this morning around 7:45 ET, reported elated scientists from the European Space Agency, who are eagerly awaiting data about the cloud-shrouded moon.

"We have a signal. We know that Huygens is alive meaning the dream is alive," said Jean-Jacques Dordain director general for ESA which designed Huygens. "This is already an engineering success and we will see, later this afternoon, if this is a scientific success."

Grinning scientists watching from the ESA operations center in Germany said the first obstacle -- a tricky atmospheric entry -- had been a great engineering feat. Time will tell if all of Huygens' precious data will reach Earth. The probe will continue sending data until its batteries run out or Cassini, the satellite orbiting Saturn relaying Huygens' signal, passes over the moon's horizon in about two hours' time.

"So far so good," said David Southwood, director of science for ESA. "The signal has been solid for a long time."

The saucer-shaped probe is completing the final hours of its 2.2 billion-mile mission to study the icy world. It plunged through the orange clouds of Saturn's moon Titan early Friday morning deploying three parachutes to slow down from a blistering reentry speed.

Jean-Pierre Lebreton, Huygens project scientist, said the first data from a Doppler wind experiment were reaching Earth and more data would arrive throughout the morning. Radio telescopes around the world are tracking Huygens' signal.

When the first images arrive this afternoon, scientists will have their long-anticipated glimpse at an alien world.

"It's going to be the most exotic place we've ever seen," said Candice Hansen, a scientist for the Cassini-Huygens mission. "We've never landed on the surface of an icy satellite. We know from our pictures that there are very different kinds of geological processes."

The Cassini-Huygens mission is an unprecedented $3.3-billion effort between NASA, the European Space Agency and Italy's space program to study Saturn and its 33 known moons. The two vehicles were launched together from Florida in 1997.

"The mission is to explore the entire Saturnian system in considerably greater detail than we have ever been able to do before: the atmosphere, the internal structure, the satellites, the rings, the magnetosphere," said Cassini program manager Bob Mitchell at NASA.

The Huygens probe, about the size of a Volkswagen Beetle, has been spinning silently toward Titan since it detached from the Cassini spacecraft on December 24. Cassini will remain in orbit around Saturn until at least July 2008.

The mission "will probably help answer some of the big questions that NASA has in general about origins and where we came from and where life came from," Mitchell said.

Titan's atmosphere, a murky mix of nitrogen, methane and argon, resembles Earth's more than 3.8 billion years ago. Scientists think the moon may shed light on how life began.

Finding living organisms, however, is a remote possibility. "It is not out of the question, but it is certainly not the first place I would look," Hansen said. "It's really very cold." A lack of sunlight has put Titan into a deep-freeze. Temperatures hover around -292 F (-180 C) making liquid water scarce and hindering chemical reactions needed for organic life.

New discoveries
The mysteries of Saturn, the sixth planet from the sun, have always enticed researchers. Scientists are perplexed why Saturn, a gas-giant composed primarily of hydrogen and helium, releases more energy than it absorbs from faint sunlight. Titan is also the only moon in the solar system to retain a substantial atmosphere, one even thicker than Earth's.

The 703-pound, battery-powered Huygens probe parachuted through Titan's clouds of methane and nitrogen for two-and-a-half hours, sampling gases and capturing panoramic pictures along the way.

Huygens hit the upper atmosphere 789 miles (1,270 km) above the moon at a speed of about 13,700 mph (22,000 km/h). A series of three parachutes slowed the craft to just 15 mph (24 km/h). Chutes and special insulation protect Huygens from temperature swings and violent air currents. Strong winds -- in excess of 311 mph (500 km/h) -- buffeted the craft, capable of dragging Huygens sideways after its parachute was deployed.

Its sensors can deduce wind speed, atmospheric pressure and the conductivity of Titan's air. Methane clouds and possibly hydrocarbon rain will be analyzed by an onboard gas chromatograph. A microphone will listen for thunder.

Three rotating cameras are snapping panoramic views of the moon, capturing up to 1,100 images. A radar altimeter is mapping Titan's topography and a special lamp illuminated the probe's landing spot to help determine the surface composition.

Engineers were confident that Huygens and its suite of six sensitive instruments would survive the descent.

"From an engineering standpoint, I'm very confident in a positive outcome," said Shaun Standley, an ESA systems engineer for Huygens at the Jet Propulsion Laboratory in California. "We've been over this again and again for the last three years fine-tuning this."

Cassini crossed Saturn's rings without mishap in June 2004 and produced the most revealing photos yet of the rings and massive gas-giant. A problem with the design of an antennae on Cassini almost scrapped Huygens' mission, but engineers altered the spacecrafts' flight plans to resolve the transmission problem.


beam me up Scotty

LittleMilkJug

LittleMilkJug

from BBC



The Huygens space probe has sent back its first set of data about Saturn's largest moon, Titan, after landing successfully say space scientists.
The spacecraft probe had still been transmitting data for over two hours after it had landed they confirmed.

"We are the first visitors to Titan," said an excited Jean-Jacques Dordain, director general of the European Space Agency (Esa).

It is also the furthest from Earth a spacecraft has ever been landed.

"In the morning we had an engineering success and this afternoon we can also say we have a scientific success," he added.

Scientists were now piecing together the data, images, measurements and sounds that was being beamed back to Earth.

"We're going to be working very hard in the next hours and days. This data is data for posterity," said Professor David Southwood, Esa's director of science.

The sounds of Titan's stormy atmosphere were recorded with an onboard microphone, and scientists hope that they might even hear lightning strikes when they analyse the data.

Signal excitement

Scientists were excited when the probe first relayed a signal to say it had negotiated Titan's atmosphere, and announced that the mission was a "success".

"I want to make sure that we don't miss the significance of seeing that signal," said Alphonso Diaz, associate administrator for science at the US space agency (Nasa).



Huygens is transmitting scientific data to its mothership Cassini, which is orbiting in space, for onward transmission to Earth.

The orbiter turned towards our planet and sent the first packets of information.

These were received by the European space operations centre in Darmstadt, Germany, ready for scientific analysis.

The first signal from Huygens was picked up by radio telescopes in West Virginia, US between 1020 and 1025 GMT on Friday.

This told them that the pilot parachute had pulled off the probe's rear cover, allowing its antenna to start transmitting, and that its instruments were working.

When the European-built probe entered Titan's atmosphere at an altitude of 1,270km (789 miles) from the surface, it was travelling at over Mach 20 which is 20 times the speed of sound.

Once friction slowed the probe's descent to about Mach 1.5, it deployed the first of three parachutes, pulling off the rear cover that protected Huygens from the fierce heat as it entered the atmosphere.

Unknown surface

Titan is veiled by a thick orange haze which obscures its surface features. Huygens could have land with a thud on ice and rock, squelched into tar-like gunge, or splashed down in an oily sea.

HUYGENS' INSTRUMENTS

1. HASI - measures physical and electrical properties of Titan's atmosphere
2. GCMS - identifies and measures chemical species abundant in moon's 'air'
3. ACP - draws in and analyses atmospheric aerosol particles
4. DISR - images descent and investigates light levels
5. DWE - studies direction and strength of Titan's winds
6. SSP - determines physical properties of moon's surface


Hopes ride on Huygens
Huygens probe 'looks good'
Cassini's goodbye Huygens snap
The spacecraft should have taken about 750 images during its two-and-a-half-hour descent, shedding light on this cosmic enigma.

"This should provide a spectacular new view of Titan and hopefully a much greater understanding of this mysterious world," said Marty Tomasko, principal investigator on the Descent Imager/Spactral Radiometer instrument on Huygens.

Professor John Zarnecki, principal investigator on the surface science package on Huygens, has made no secret of his wish to land on an extraterrestrial ocean.

"I'm pleased that my instrument has got something to measure a liquid surface, a solid surface and something in between," he told the BBC News website.

"Despite the flybys of Titan by Cassini we still don't know [what its surface is like]."

Data gathered by the spacecraft should give detailed information on the moon's weather and chemistry.

Dominated by nitrogen, methane and other organic (carbon-based) molecules, conditions on Titan are believed to resemble those on Earth 4.6 billion years ago.

As such, it may tell scientists more about the kind of chemical reactions that set the scene for the emergence of life on Earth.

Huygens has spent the past seven years tethered to the Cassini spacecraft, which arrived at Saturn in July 2004.

It had been coasting silently towards the exotic world for 20 days after being released from its mothership Cassini on 25 December.

LittleMilkJug

I for one think this very exciting. I was reading on the CNN site that there are seas of liquid methane on Titan

No1important

To me. This is much more intriguing than the Rovers on Mars. I guess because of the distance and we do not know too much about Titan.

Suga*Babe

Very cool. I hadn't heard about it before, should pay more attention to the news I guess

LittleMilkJug

Its minus 180 degree's on Titan Don't forget to bring your gloves!!

Excuse my non-scientific way of putting things but isn't methane very explodable??

Superabo

That's totally cool. I'm really, really happy humankind is making these scientific advances. I hope we can explore even farther one day.

Yeah, LittleMilkJug, I believe methane is combustible.

No1important

I am curious about that myself. If the probe sparked, you would think the moon would blow up and I assume ESA would be aware of that. So it makes sense that Titan is missing a element or gas to cause it to explode?

I may be wrong but I will try and find an answer.

I emailed David Dodge at the H.R. Macmillan Planetarium in Vancouver, so hopefully he has an answer. I will post it when I get a response.

JW77

There's no oxygen on Titan. That's why it won't spark.

Anyway, I'm very excited about this. But then again, I always am....I love this kind of stuff.

No1important

Thank you JW77 for the answer. Most appreciated. I figured there had to be a simple explanation.

LittleMilkJug

There you go! I totally forgot that fire needs good old oxygen I had images of that horrific Zepplin disaster!

No1important

Well we know its oxygen that is missing. But he mentioned something else that was a little interesting in his reply.

[b]The missing ingredient is oxygen. Indeed, some of my colleagues were speculating that any future Titan exploration machine (that used an engine) would need to provide fuel in the form of oxygen and would ingest the atmosphere and use the combination of the ‘fuel’ and ‘air’ in the opposite mode as we use them here on Earth.[/b

LittleMilkJug

I guess Sun-panels(like they use on Mars) are out of the question, with the Sun being so far away .