Live Huygens descent and landing commentary provided by ESA is being webcast on NASA TV.

LIVE Coverage of Huygens' Titan Descent

11:40: Huygens worked "beautifully" according to ESA Director-General Jean-Jacque Dordain.

"The morning was good, the afternoon is better," Dordain said. "We have a scientific success."

11:35 a.m. EST: It's confirmed! Huygens has successfully returned science data from Titan's surface. The probe's landing is the farthest touchdown for any human-built object to set land on another world.

A news briefing on Huygens' apparent success is underway and its thumbs-up all around for mission scientists and managers.

11:19 a.m. EST: Shouts and applause erupted from Huygens mission control, and presumably some data from the probe has apparently arrived.

"We have it? We have it!" said one mission team member before the shouts.

Stand by for confirmation.

11:15 a.m. EST: ESA officials had said earlier today that they anticipated the first science from Huygens at this time. So far, no word on the status of science data from the Titan probe.  

11:12 a.m. EST: There is some discussion, from talk broadcast from ESOC's main control room, that it may be another seven minutes for the first Huygens data.

11:00 a.m. EST: ESA and NASA Huygens team members are still waiting to see the first data sent by the probe from Saturn's hazy moon Titan. At ESA's ESOC spacecraft operations center in Darmstadt, Germany, personnel are steadily gathering around computer consoles in anticipation.

10:35 a.m. EST: It's confirmed. Cassini has turned back to the Earth and is sending data. No Huygens probe data has been downloaded yet, but researchers are waiting expectantly.

"We have 40 more minutes of suspense, then we'll know if everything worked properly," said John Dodsworth, Huygens ground manager at ESOC.

10:30 a.m. EST: Applause broke out briefly at ESA's ESOC spacecraft operations center in Darmstadt, Germany. Apparently, mission controllers have detected the first data from Cassini's Huygens receivers, spacecraft engineers said.

That doesn't mean that any Huygens science has arrived, just that the receivers aboard Cassini designed to record that data were functioning at the start of the descent, they added. 

10:15 a.m. EST: Huygens is still pounding out a signal to the surprise of ESA engineers, but any science data it is currently transmitting is falling on deaf ears.

The Cassini orbiter, Huygens' only connection to Earth, has turned away from the probe and is preparing to relay the probe's data home, mission controllers said.

10:00 a.m. EST: Engineers at JPL said that although Huygens' data will first be received at JPL, it will be forwarded straight to ESA's ESOC spacecraft operations center in Germany where hundreds of scientists and engineers are eagerly awaiting news from the Titan probe.

9:50 a.m. EST: As ESA commentators take a break in Darmstadt, Germany, researchers and engineers at NASA's Jet Propulsion Laboratory in Pasadena, California are lauding Huygens' apparently successful landing on Titan.

 “There are a lot of excited people in Darmstadt and here too,” said ESA Huygens system engineer Shaun Standley at JPL.

9:45 a.m. EST: By 10 a.m. EST, mission managers expect Cassini to have begun to swing back to point toward Earth and deliver the first packets of information from the Huygens probe on Titan.

9:20 a.m. EST: NASA's Cassini orbiter has a quadruple redundant data recording capability, meaning the spacecraft is collecting Huygens data with four redundant systems in hopes of ensuring that no information is lost, ESA officials said.

"We really don't want to lose any bit of this precious data," ESA mission operations manager Claudio Solazzo said earlier today.

9:10 a.m. EST:  “The probe is still alive and sending a signal,” said Claudio Solazzo, ESA Huygens mission operations manager.  

Now that Huygens is apparently on Titan, researchers hope a pair of electronic levels will register any movement of the probe. If it landed on a hydrocarbon lake, the levels would detect any bobbing motion, researchers have said. 

A penetrating instrument on Huygens' bottom should make a very simple measurement upon landing to determine if the landing zone is firm, clay, sand or other type of surface, Huygens mission scientists said.

8:35 a.m. EST: Huygens mission controllers report that the probe landed somewhere between 1:45 p.m. and 1:46 p.m. local time in Darmstadt, Germany (CET), that's somewhere between 7:45 a.m. and 7:46 a.m. EST.  

The probe is apparently on Titan's surface and still going strong, mission managers said.

8:00 a.m. EST: The first Huygens news briefing post-Titan descent has concluded.

ESA mission managers said Huygens' carrier signal, the only signal researchers expected to detect from Earth, has also been detected by the Parkes radio telescope in Australia. The signal has been blaring strong for two hours now, researchers said.

Mission manager Jean-Pierre Lebreton said that four optical telescopes around the world were trained on Titan during Huygens' descent. One telescope was unable to observe the event due to poor weather, while the other three failed to detect any sign of a entry fireball, he added.

The first real telemetry from Huygens should reach Earth around 10:21 a.m. EST (1521 GMT), though it will be 4:21 p.m. local time at ESOC in Darmstadt, Germany. The first science data is anticipated to arrive by 11:15 a.m. EST (1615 GMT), mission controllers said.

7:45 a.m. EST: At least one instrument aboard Huygens is taking data. A Doppler instrument designed to track wind patterns on Titan is apparently working, Jean-Pierre Lebreton, Huygens mission manager, said during the press conference.

7:20 a.m. EST: The first news briefing on today's Huygens descent to Titan should begin in about 10 minutes at ESA's ESOC spacecraft operations center. Huygens reached Titan successfully about two hours ago, and should have touching down on the moon's surface at 7:34 a.m. EST according to a NASA mission timeline.

6:45 a.m. EST: ESA officials say the mood at ESOC has eased with the Huygens signal detection by West Virginia's Green Bank Telescope. Nail-biting tension has been replaced with some relief, though Huygens mission scientists are still eager to learn if their science instruments are taking measurements as designed.

"We're now just waiting for Cassini," John Dodsworth said earlier.

6:15 a.m. EST: With the confirmation signal from Huygens in hand, ESA officials know the probe is currently floating down toward Titan under its main parachute. It will jettison the parachute as it descends and deploy a smaller, three-meter parachute in order to reach the surface before onboard batteries run out, mission managers said today.

6:05 a.m. EST:

Space News Staff Writer Peter de Selding reports live from Huygens mission control:

 6:00 a.m. EST: If it switched on as planned, a microphone instrument aboard Huygens may allow researchers to recreate the sound of the probe's descent as it plunged through Titan’s atmosphere, ESA mission scientists said. The instrument may also record thunder, and Huygens scientists hope to have at least initial data to present within 24 hours.

5:50 a.m. EST: Cautious ESA commentators stress the Huygens signal is just a carrier tone. There is no confirmation that the six science instruments aboard the probe are working as planned.

"It looks like we heard the baby crying," said Huygens mission manager Jean-Pierre Lebreton from the floor of ESOC mission control. "But clearly it tells us the probe is alive, the entry has been successful and we are under parachutes."

5:35 a.m. EST: Huygens speaks from Titan! ESA has confirmed that the Green Bank Telescope successfully detected a Huygens signal tone. The signal, a confirmation that Huygen's transmitter is at least functioning, and activated on time at about 5:18 a.m. EST.

About 600 people are at ESOC mission control for Huygens Titan descent and some engineers crowded around computer monitors when the signal confirmation was announced.

"It's a tremendously exciting moment," said John Dodsworth, Huygens ground manager at ESOC.

5:30 a.m. EST: If everything is going well, researchers may be able to assemble Huygens first pictures of Titan within 24 hours, U.S. astronomer Martin Tomakso, the international lead of the probe's only optical instrument, has said.

“The first images may be pretty murky,” Tomasko said from Darmstadt, adding that Titan’s nitrogen-rich atmosphere is quite hazy. “But we think the haze has a bottom, and that once we get through it we’ll have a clear view of the surface.”

Tomasko said that during its slow descent, Huygens will most likely be swinging and rocking while taking numerous images that will later have to be assembled into mosaics. The Sun should appear 10 times smaller from Titan than it does from Earth, so researchers expect a sort of twilight environment, he added.

5:15 a.m. EST: According to its timeline, Huygens should now be transmitting data to its Cassini mothership, after deploying a series of parachutes to slow its descent. The first few measurements could already be in Cassini's data file, researchers say. But they will not know for sure whether Huygens transmitter is working unless Green Bank is successful in picking up the tone, or from Cassini once it turns back toward Earth.

5:00 a.m. EST: ESA's Huygens probe is scheduled to reach Titan in the next few minutes. While all Huygens data will be recorded by Cassini for later playback to Earth, astronomers are hoping that the powerful 100 by 110-meter Green Bank radio telescope in West Virginia will pick up a simple tone from the probe.

4:15 a.m. EST: Al Diaz, NASA's associate administrator of the Science Mission Directorate, is monitoring the joint Cassini-Huygens operations at ESA's ESOC mission control center in Darmstadt.

"It's a mission unlike anything we've tried before," he said today of Cassini-Huygens.

4:00 a.m. EST: ESA is providing a real time tracking of Cassini and Huygens. You can see find it here. At last report, Huygens was set to reach Titan at about 5:05 a.m. EST, then deploy parachutes a few minutes later. The Cassini orbiter was last reported about 72,000 kilometers from Titan. It has turned away from Earth to record any data Huygens is able to broadcast.

3:30 a.m. EST: ESA mission controllers are playing a waiting game now with Huygens' mothership Cassini. The NASA orbiter has apparently turned away from Earth and is oriented toward Titan to receive data fromthe Huygens probe.

European commentators have their fingers crossed that Huygens' descent goes better than a recent - but fictional - probe to Titan in the BBC science fiction series Space Odyssey. In that series, which follows a crew of astronauts exploring the solar system, an automated Titan probe fails after deployement.

3:25 a.m. EST:  Huygens mission controllers report the probe is hurtling toward Titan at about 22,000 kilometers an hour.

3:20 a.m. EST:  John Dodsworth, of ESA's ESOC mission control center at Darmstadt, said Huygens is about two hours from reaching Titan interface - about 1,270 kilometers above the surface. The probe is right on target and will land well within its target, he added. 

3 a.m. EST: ESA officials are counting down to the Huygens probe's arrival at Titan. The probe is still a few hours off from encountering the moon's atmosphere.

"I certainly am jumping all over in anticipation," said Claudio Solazzo, ESA Huygens Mission operations manager, from Darmstadt, Germany. "Today is a great day."