samedi 26 novembre 2011

NASA Launches Most Capable and Robust Rover to Mars

NASA - Mars Science Laboratory (MSL) Mission patch.

Nov. 26, 2011

 Atlas V Lifts Off with MSL

NASA began a historic voyage to Mars with the Nov. 26 launch of the Mars Science Laboratory, which carries a car-sized rover named Curiosity. Liftoff from Cape Canaveral Air Force Station aboard an Atlas V rocket occurred at 10:02 a.m. EST (7:02 a.m. PST).

Image above: NASA's Mars Science Laboratory lifts off from Cape Canaveral Air Force Station, Fla. Photo by Pat Corkery, United Launch Alliance.

"We are very excited about sending the world's most advanced scientific laboratory to Mars," NASA Administrator Charles Bolden said. "MSL will tell us critical things we need to know about Mars, and while it advances science, we'll be working on the capabilities for a human mission to the Red Planet and to other destinations where we've never been."

The mission will pioneer precision landing technology and a sky-crane touchdown to place Curiosity near the foot of a mountain inside Gale Crater on Aug. 6, 2012. During a nearly two-year prime mission after landing, the rover will investigate whether the region has ever offered conditions favorable for microbial life, including the chemical ingredients for life.

"The launch vehicle has given us a great injection into our trajectory, and we're on our way to Mars," said Mars Science Laboratory Project Manager Peter Theisinger of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The spacecraft is in communication, thermally stable and power positive."

The Atlas V initially lofted the spacecraft into Earth orbit and then, with a second burst from the vehicle's upper stage, pushed it out of Earth orbit into a 352-million-mile (567-million-kilometer) journey to Mars.

The MSL spacecraft separates and heads on its way to Mars

"Our first trajectory correction maneuver will be in about two weeks," Theisinger said. "We'll do instrument checkouts in the next several weeks and continue with thorough preparations for the landing on Mars and operations on the surface."

MSL Spacecraft Mars Bound

Curiosity's ambitious science goals are among the mission's many differences from earlier Mars rovers. It will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover. Curiosity carries 10 science instruments with a total mass 15 times as large as the science-instrument payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking the elemental composition of rocks from a distance, and an X-ray diffraction instrument for definitive identification of minerals in powdered samples.

To haul and wield its science payload, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. Because of its one-ton mass, Curiosity is too heavy to employ airbags to cushion its landing as previous Mars rovers could. Part of the Mars Science Laboratory spacecraft is a rocket-powered descent stage that will lower the rover on tethers as the rocket engines control the speed of descent.

The mission's landing site offers Curiosity access for driving to layers of the mountain inside Gale Crater. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

 Mars Science Laboratory at the surface of Mars (Artist's view)

Precision landing maneuvers as the spacecraft flies through the Martian atmosphere before opening its parachute make Gale a safe target for the first time. This innovation shrinks the target area to less than one-fourth the size of earlier Mars landing targets. Without it, rough terrain at the edges of Curiosity's target would make the site unacceptably hazardous.

The innovations for landing a heavier spacecraft with greater precision are steps in technology development for human Mars missions. In addition, Curiosity carries an instrument for monitoring the natural radiation environment on Mars, important information for designing human Mars missions that protect astronauts' health.

The mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. NASA's Launch Services Program at the Kennedy Space Center in Florida managed the launch. NASA's Space Network provided space communication services for the launch vehicle. NASA's Deep Space Network will provide spacecraft acquisition and mission communication.

For more information about the mission, visit: and

For more information about the Deep Space Network, visit:

Images, Videos, Text, Credit: NASA / Dwayne Brown / JPL / Guy Webster / NASA TV.

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vendredi 25 novembre 2011

Successful launch of Proton-M with the spacecraft "Asiasat-7"

ROSCOSMOS / ILS - AsiaSat-7 Mission poster.


AsiaSat-7 launch

November 25 to 23 hours 10 minutes. Moscow with a launcher platform 39 200 Baikonur calculations starting enterprises of rocket and space industry in Russia is produced starting of space rocket "Proton-M" with the upper stage "Breeze-M" and the spacecraft "Asiasat-7."

Asiasat-7 satellite

After regular office from the third stage rocket upper stage "Breeze-M" spacecraft continues removing "Asiasat-7" to the desired orbit.

The Satellite

  • Satellite Operator: AsiaSat
  • Satellite Manufacturer: Space Systems/Loral
  • Purpose: Satellite Broadband
  • Platform: SS/L 1300
  • Separated Mass: 3,813 kg
  • Satellite Design Life: 15 years
Separation of the spacecraft from the upper stage is scheduled for 8 hours 23 minutes Moscow time on 26 November.

Original text in Russian:

Image, Video, Text, Credits: Press Service of the Russian Space Agency (Roscosmos PAO) / ILS / Translation:


ESA station unable to establish new link with Phobos-Grunt

ESA / ESOC logo.

25 November 2011

UPDATE After establishing contact with Russia's Phobos-Grunt Mars mission earlier this week, ESA's tracking station in Australia received no signal from the spacecraft last night. ESA engineers are investigating the cause in close collaboration with Russian mission controllers.

Despite listening intently during four scheduled communication passes during the night of 24–25 November, ESA's 15 m-diameter dish antenna at Perth, Australia, did not receive any signals .

ESA's 15m tracking station, Perth, Australia

The slots for communication, timed to coincide when Phobos–Grunt was passing over in direct line-of-sight with the station, began at 20:12 GMT and ran until 04:04 GMT. Each lasted just 6–8 minutes, providing very limited windows for sending commands and receiving a response.
“The team here at ESOC will do their utmost to assist the Russians in investigating the situation.”

"Our Russian colleagues provided a full set of telecommands for us to send up," said Wolfgang Hell, ESA's Phobos–Grunt Service Manager, "and Perth station was set to use the same techniques and configurations that worked earlier. But we observed no downlink radio signal from the spacecraft."

Phobos-Grunt spacecraft

ESA's contact with the Mars mission on the night of 22 November marked the first receipt of spacecraft data since contact was lost shortly after separation from the launch vehicle was confirmed on 8 November.

One piece of positive news: observations from the ground indicate that the orbit of Phobos–Grunt has become more stable.

"This could mean that the spacecraft's attitude, or orientation, is also now stable, which could help in regaining contact because we’d be able to predict where its two antennas are pointing," said Manfred Warhaut, ESA's Head of Mission Operations at the European Space Operations Centre, Darmstadt, Germany.

"The team here at ESOC will do their utmost to assist the Russians in investigating the situation."

UPDATE 25.11 14:30 GMT - The next scheduled communication slot for ESA's Perth station is set for the night of 25 November, when it will again be allocated to support Phobos–Grunt.

Related links:

ESTRACK ground stations:

Phobos-Soil mission:

More information:

NPO Lavochkin:


Images, Text, Credits: ESA / ROSCOSMOS / Lavochkin Association.


JAXA - AKARI operation completed

JAXA / ISAS AKARI Mission patch.

November 25, 2011

Japan Aerospace Exploration Agency reported that operation of the infrared astronomical satellite AKARI (ASTRO-F) was completed. The onboard transmitters were turned off at 17:23 (JST) on the November 24, 2011.

AKARI in space

AKARI was launched on February 22 (JST), 2006 from the Uchinoura Space Center by the M-V Launch Vehicle No. 8. It is the first Japanese infrared astronomical satellite, and has been operated beyond its expected lifetime(*). AKARI provided infrared source catalogues containing 1.3 million objects as well as many essential outcomes in the infrared astronomy.

Major results provided by AKARI

AKARI's science operation was completed in June 2011 following a trouble in its power-supply system happened on the May 24, 2011. After then efforts for safe termination have been continued.

Major results provided by AKARI are reported in the following pages as well as the project's science result page.

AKARI Project Site > Results:

Current Status of the AKARI Mission After one year of observations --- The Universe as seen by AKARI (Topics:July 11, 2007):

AKARI's recent highlight (Topics:November 19, 2008):

(*) The required lifetime is one year and target lifetime is three years.

Mission website:

Infrared Imaging Satellite "AKARI" (ASTRO-F):

Images, Text, Credit: Japan Aerospace Exploration Agency (JAXA).


jeudi 24 novembre 2011

ESA station keeps contact with Russian Mars mission Phobos-Grunt

ESA / ESOC logo.

24 November 2011

Following the first successful contact on Tuesday, ESA's tracking station in Australia again established two-way communication with Russia's Phobos–Grunt spacecraft on 23 November. The data received from the spacecraft have been sent to the Russian mission control centre for analysis.

ESA's 15 m-diameter antenna at Perth, Australia, was again used to contact Russia's Phobos–Grunt spacecraft during the night of 23–24 November, with a total of five communication passes available between 20:19 and 04:08 GMT.

Tracking station control room at ESA's Space Operations Centre

Teams working at the Perth station and at ESA's Space Operations Centre, Darmstadt, Germany, were delighted to see a clear signal during the first of the passes. 

Telemetry received via Perth station

"The first pass was successful in that the spacecraft's radio downlink was commanded to switch on and telemetry was received," said Wolfgang Hell, ESA's Service Manager for Phobos–Grunt.

ESA's 15m tracking station, Perth, Australia

Telemetry typically includes information on the status and health of a spacecraft's systems.

"The signals received from Phobos–Grunt were much stronger than those initially received on 22 November, in part due to having better knowledge of the spacecraft's orbital position."

The second pass was short, and so was used only to uplink commands – no receipt of signal was expected.

However, the following three passes in the early morning of 24 November proved to be more difficult: no signal was received from Phobos–Grunt.

ESA engineers assist Russian mission controllers

Working with Russian mission controllers, ESA engineers are carefully studying the situation, which may be related to the spacecraft's communication system. During last night's first two passes, one of the two low-gain antennas on Phobos–Grunt was, due to the spacecraft's orbital position, oriented toward Perth, and communications worked.

Phobos-Grunt orbiter and lander Mission poster

During the three later passes, the spacecraft's orbital position changed, and the second, opposing, antenna had to be used – but no signal was received.

"Our Russian colleagues will use this result for troubleshooting and to plan their commands for us to send tonight," says Manfred Warhaut, ESA’s Head of Mission Operations.

Communication support continues tonight

ESA engineers will work today to provide advice and assistance on possible communication strategies to consolidate the contact now established with the mission.

Another five communication slots are available during the night of 24–25 November, and the Perth tracking station will again be allocated on a priority basis to Phobos–Grunt.

More news will follow as the situation develops.

Related Links:

ESTRACK ground stations:

Phobos-Soil mission:

NPO Lavochkin:


Images, Text, Credits: ESA / SpaceTerra / Lavochkin Association.


Mars Express steadily returns to routine operation

ESA - Mars Express Mission patch.

24 November 2011

Mission controllers are making excellent progress in returning Mars Express to routine service. Some science activities have already resumed after being temporarily suspended last month following a series of faults related to the onboard data storage system.

Having arrived around Mars in December 2003 for an initial two-year mission, the spacecraft is now in its eighth year of science operations. It has returned some of the most stunning images and valuable science data ever obtained from the Red Planet.

Mars Express

In mid-October 2011, anomalies in the operation of its Solid-State Mass Memory (SSMM) system caused science observations to be temporarily halted.

The problem had surfaced several weeks earlier, when, on several occasions, the spacecraft autonomously entered safe mode. This is an operational mode designed to safeguard both the spacecraft and its instrument payload in the event of internal faults or errors. 

Data storage problems

The cause was a complex combination of events relating to reading from and writing to memory modules in the SSMM system.

This is used to store data acquired by the instruments and housekeeping data from the spacecraft's subsystems, prior to transmission to Earth. It is also used to store commands that have been received from ground stations while awaiting execution.

“This problem was unanticipated by the spacecraft designers, so everyone on the mission control team is learning as we go.”

The mission control team at ESOC, ESA's Space Operations Centre, Darmstadt, have been working closely with technical experts from the spacecraft's manufacturer as well as other experts at ESA to troubleshoot and isolate the problem. However, it has not been possible to date to understand nor resolve the problem with the SSMM directly.

Therefore the team are now designing a series of new procedures that will enable commands to be stored without critical dependency on the problem-plagued SSMM.

Working intensively

"The entire team have worked intensively to implement a provisional fix. Limited science observations were able to resume on 31 October," said Michel Denis, Mars Express Spacecraft Operations Manager.

Combined planetary mission Dedicated Control Room at ESOC

"This problem was unanticipated by the spacecraft designers, so everyone on the mission control team is learning as we go."

The newly designed approach implies that commands will now be sent up in much smaller batches, and that additional protections will be implemented to avoid safe mode or an unpredictable spacecraft status should one of the command batches fail to execute.

“Solving this problem is like writing a really terrific mystery novel.”

"This has been our first permanent anomaly in eight years of orbit," said James Godfrey, Mars Express Spacecraft Operations Engineer. "Solving it is like writing a really terrific mystery novel."

By mid-November, the spacecraft had returned to gathering science observations for longer periods during each orbit, one instrument at a time. The team expect that combined science operations with all instruments will resume in early 2012.

"We're still studying the issue to formulate a long-term solution, and we're aiming to return to as high a level of normal science operations as possible – quite close to 100%, actually," said Denis.

"The team are doing an excellent job at designing ingenious and safe solutions; I'm very impressed with their skills and dedication to our otherwise very fit spacecraft."

More information:

Mars Express overview:

Mars Express in-depth:

Mars Express Science Operations Centre:

Images, Text, Credits: ESA / D. Ducros / J. Mai -


mercredi 23 novembre 2011

ESA tracking station establishes contact with Russia’s Mars mission

ESA / ESOC logo.

23 November 2011

On Tuesday, 22 November at 20:25 GMT, ESA's tracking station at Perth, Australia, established contact with Russia's Phobos-Grunt spacecraft. Contact with the Mars mission was lost shortly after separation from the launch vehicle was confirmed on 8 November.

Following liftoff, the spacecraft was injected into low-Earth orbit in preparation for departure to Mars. Immediately after separation of the spacecraft and its modified Fregat stage from the launcher, controllers received signals confirming deployment of the solar panels.

ESA's 15m tracking station, Perth, Australia

Two automated burns of the Fregat engine were to have taken place beyond coverage of Russian ground stations, boosting it onto an interplanetary trajectory for the Red Planet. These failed to happen and contact was lost from that moment. However, observations showed that the craft was in a controlled attitude orbiting Earth between about 200 km and 340 km altitude. 

ESA responds to Russian request for assistance

Upon request from NPO Lavochkin, operator of the mission on behalf of the Russian space agency, Roscosmos, ESA agreed to do its utmost to attempt contact using the Agency’s ground station network.

Starting on 9 November, and in close coordination with Russian engineers, ESA made almost daily attempts to contact Phobos-Grunt using numerous configurations and radio link modes, but to no avail.

Phobos-Grunt orbiter and lander

A major problem was that the spacecraft's orbit was not accurately known, whereas ground stations normally require very accurate position information for pointing due to the antenna size.

In the past few days, ESA's 15 m-diameter Perth dish was modified by the addition of a 'feedhorn' antenna at the side of the main dish so as to transmit very low-power signals over a wide angle in the hopes of triggering a response from the satellite.

The transmit power was reduced in part because the receiver on Phobos-Grunt is optimised to receive only very weak signals when deep in space.

Low-power feedhorn antenna contacted Phobos-Grunt

Perth is ideally located because the satellite's solar panels were illuminated by sunlight when overhead, giving a power boost to its systems.

ESA station in Australia transmits Russian telecommands

On 22 November, the Perth station antenna was pointed toward the spacecraft's expected orbital position during 20:21–20:28 GMT, and telecommands provided by NPO Lavochkin were transmitted.

"Owing to its very low altitude, it was expected that our station would only have Phobos-Grunt in view for six to ten minutes during each orbit, and the fast overhead pass introduced large variations in the signal frequency," said Wolfgang Hell, the Phobos-Grunt Service Manager at ESOC.

Hard work pays off

ESOC: home to ESA's mission operations

Despite these difficulties, it was a success: the signals commanded the spacecraft's transmitter to switch on, sending a signal down to the station's 15 m dish antenna.

Data received from Phobos-Grunt were then transmitted from Perth to Russian mission controllers via ESA's Space Operations Centre, Darmstadt, Germany, for analysis.

Additional communication slots are available on 23 November at 20:21–20:28 GMT and 21:53–22:03 GMT, and ESA teams are working closely with Russian controllers to determine how best to maintain communication with their spacecraft.

More news will follow as the situation develops.

Related links:

ESTRACK ground stations:

Phobos-Soil mission:

NPO Lavochkin:


Credits: ESA / J. Mai / Lavochkin Association.


Closing in on the Higgs

CERN - European Organization for Nuclear Research logo.

23 Nov 2011

 The combined results as presented by ATLAS and CMS

On the final day of the Hadron Collider Physics symposium, HCP2011, the ATLAS and CMS experiments presented their first combined analysis on the search for the Higgs boson. A cornerstone of the Standard Model of particle physics, which describes fundamental particles and their interactions, the Higgs boson is among the top priorities for the research programme at the Large Hadron Collider. The study of ATLAS and CMS includes data collected up to the end of July, and rules out the existence of a Higgs boson with mass between 141 and 476 GeV at the 95% confidence level. If the Higgs boson exists, it must have a mass between 114 and 141 GeV. The LHC experiments will be able to demonstrate its existence, or show that it does not exist, during the course of 2012.

Getting around the LHC


The European Organization for Nuclear Research (French: Organisation européenne pour la recherche nucléaire), known as CERN, is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border. Established in 1954, the organization has twenty European member states.

The term CERN is also used to refer to the laboratory itself, which employs just under 2400 full-time employees/workers, as well as some 7931 scientists and engineers representing 608 universities and research facilities and 113 nationalities.

More information:

The combined results as presented by ATLAS and CMS on the Atlas website:
On the CMS website:

Images, Text, Credit: CERN.

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ESA opens Landsat archives


23 November 2011

Over 30 years of archived data from the US Landsat Earth-observing satellites are now available, free of charge. The majority of these products are unique to ESA’s archive and have never before been accessible anywhere else by the scientific user community.

In its archives, ESA holds around two million products that cover Europe and North Africa. The total amount of data available is worth about 450 terabytes – that’s equivalent to about 900 000 hours of audio recorded at CD quality.

Mar de plastico, Spain

ESA has been acquiring Landsat data at European stations since the 1970s.

“The missions were the main data source for many years during the 1980s when Earth observation started at ESA’s ESRIN centre in Italy,” said Gunther Kohlhammer, Head of the Ground Segment Department.

ESA revised its Earth observation data policy in 2010 to adapt to the ‘Joint Principles for a Sentinel Data Policy’. This policy was approved by ESA Member States participating in the GMES Space Component Programme, and supports the concept of providing free and open access to data.

By revising the data policy, ESA followed the same path as the US Geological Survey, who began making its Landsat data available free of charge in 2009. 

Rotterdam, Netherlands

The ESA archives opens access to all products from the Thematic Mapper and Enhanced Thematic Mapper instruments aboard the Landsats. Data from the older Multispectral Scanner will be made available at a later stage.

To access the data, users can go to the Earth Observation Principal Investigator Portal to submit a brief project description and request data.

ESA then assigns the project a quota based on the system’s current processing capacity. When the data are ready, the user will receive directions for online retrieval.

In order to allow improved and faster access, ESA will soon begin gradually to process all data into an online archive for users to access independently. Owing to the vast amount of data, this process will take about two years.

ESA’s ESRIN centre, Italy

The Landsat series goes back to 1972, with Landsat-5 and -7 currently in orbit. Landsat-8 is due for launch by early 2013.

The 40-year-old Landsat programme is jointly managed by NASA and the US Geological Survey. ESA supports the Landsat series as a Third Party Mission, meaning it uses its ground infrastructure and expertise to acquire, process and distribute Landsat data to users.

LANDSAT satellite in orbit

“It is great finally to open the archives. We are keen to get the data to the users – especially in preparation for Sentinel-2, which is built on the heritage and knowledge of 40 years of Landsat,” says Bianca Hoersch, Third Party Mission Manager.

A Landsat image will be featured on this week’s Earth from Space video programme, broadcast online every Friday at 10:00 CET.

Related links:

Earth Observation Principal Investigator Portal:

Earth from Space video programme:

GMES Space Component Data Access:

Images, Text, Credits: USGS / ESA / NASA.


lundi 21 novembre 2011

Expedition 29 Crew Lands in Kazakhstan

ROSCOSMOS - Soyuz TMA-02M Mission patch.

Nov. 22, 2011

Expedition 29 Commander Mike Fossum and Flight Engineers Satoshi Furukawa and Sergei Volkov landed their Soyuz TMA-02M spacecraft on the steppe of Kazakhstan at 9:26 p.m. EST Monday (8:26 a.m. Tuesday Kazakhstan time), wrapping up a five-and-a-half-month mission of research and exploration.

Image above: The Soyuz TMA-02M spacecraft carrying Expedition 29 Commander Mike Fossum, Sergei Volkov and Satoshi Furukawa undocks from the International Space Station. Image Credit: NASA TV.

Volkov was at the controls of the spacecraft as it undocked at 6 p.m. EST from the International Space Station.

 Soyuz TMA-02M Re-entry Seen From Station (ISS)

Fossum, Furukawa and Volkov arrived at the orbital complex June 9 aboard Soyuz TMA-02M, joining the Expedition 28 crew as flight engineers. Expedition 29 began and Fossum took command when Expedition 28 Commander Andrey Borisenko and Flight Engineers Ron Garan and Alexander Samokutyaev departed the station in September. He, Furukawa and Volkov spent 165 days aboard the complex and 167 days in orbit.

 Soyuz TMA-02M landing

The station now is occupied by Expedition 30 Commander Dan Burbank and Flight Engineers Anton Shkaplerov and Anatoly Ivanishin. A new trio of Expedition 30 flight engineers – NASA astronaut Don Pettit, Russian cosmonaut Oleg Kononenko and European Space Agency astronaut Andre Kuipers – is slated to launch from the Baikonur Cosmodrome in Kazakhstan next month aboard Soyuz TMA-03M.

Soyuz TMA-02M capsule has landed in Kazakhstan

Watch the station crew's Thanksgiving message:

Send a postcard to the station crew:

For more information about ISS, visit:

Images, Videos, Text, Credits: Roscosmos PAO / Roscosmos TV / NASA / NASA TV.

Best regards,

Cassini Chronicles the Life and Times of Saturn's Giant Storm

NASA - Cassini-Huygens Mission patch.

Nov. 21, 2011

New images and animated movies from NASA's Cassini spacecraft chronicle the birth and evolution of the colossal storm that ravaged the northern face of Saturn for nearly a year.

These new full-color mosaics and animations show the storm from its emergence as a tiny spot in a single image almost one year ago, on Dec. 5, 2010, through its subsequent growth into a storm so large it completely encircled the planet by late January 2011.

This false-color mosaic from NASA's Cassini spacecraft shows the tail of Saturn's huge northern storm. Image credit: NASA / JPL-Caltech / Space Science Institute.

The monster tempest, which extended north-south approximately 9,000 miles (15,000 kilometers), is the largest seen on Saturn in the past two decades and is the largest by far ever observed on the planet from an interplanetary spacecraft. On the same day that Cassini's high-resolution cameras captured the first images of the storm, Cassini's radio and plasma wave instrument detected the storm's electrical activity, revealing it to be a convective thunderstorm. The storm's active convecting phase ended in late June, but the turbulent clouds it created linger in the atmosphere today.

The storm's 200-day active period also makes it the longest-lasting planet-encircling storm ever seen on Saturn. The previous record holder was an outburst sighted in 1903, which lingered for 150 days. The large disturbance imaged 21 years ago by NASA's Hubble Space Telescope and comparable in size to the current storm lasted for only 55 days.

This series of images from NASA's Cassini spacecraft shows the development of the largest storm seen on the planet since 1990. Image credit: NASA / JPL-Caltech / Space Science Institute.

The collected images and movies from Cassini's imaging team can be seen at and and . They include mosaics of dozens of images stitched together and presented in true and false colors.

"The Saturn storm is more like a volcano than a terrestrial weather system," said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena. "The pressure builds up for many years before the storm erupts. The mystery is that there's no rock to resist the pressure – to delay the eruption for so many years."

These two false-color views from NASA's Cassini spacecraft show detailed patterns that change during one Saturn day within the huge storm in the planet's northern hemisphere.Image credit: NASA / JPL-Caltech / Space Science Institute.

Cassini has taken hundreds of images of this storm as part of the imaging team's "Saturn Storm Watch" campaign. During this effort, Cassini takes quick looks at the storm in between other scheduled observations of either Saturn or its rings and moons. The new images, together with other high-quality images collected by Cassini since 2004, allow scientists to trace back the subtle changes on the planet that preceded the storm's formation and have revealed insights into the storm's development, its wind speeds and the altitudes at which its changes occur.

The storm first appeared at approximately 35 degrees north latitude on Saturn and eventually wrapped itself around the entire planet to cover approximately 2 billion square miles (5 billion square kilometers). The biggest disturbance Cassini had previously witnessed on Saturn occurred in a latitude band in the southern hemisphere called "Storm Alley" because of the prevalence of thunderstorms in this region. That storm lasted several months, from 2009 into 2010. That disturbance was actually a cluster of thunderstorms, each of which lasted up to five days or so and affected only the local weather. The recent northern disturbance is a single thunderstorm that raged continuously for more than 200 days and impacted almost one-fifth of the entire northern hemisphere.

The largest storm to ravage Saturn in decades started as a small spot seen in this image from NASA's Cassini spacecraft on Dec. 5, 2010. Image credit: NASA / JPL-Caltech / Space Science Institute.

"This new storm is a completely different kind of beast compared to anything we saw on Saturn previously with Cassini," said Kunio Sayanagi, a Cassini imaging team associate and planetary scientist at the University of California, Los Angeles. "The fact that such outbursts are episodic and keep happening on Saturn every 20 to 30 years or so is telling us something about deep inside the planet, but we have yet to figure out what it is."

Current plans to continue the mission through 2017 will provide opportunities for Cassini to witness further changes in the planet's atmosphere as the seasons progress to northern summer.

"It is the capability of being in orbit and able to turn a scrutinizing eye wherever it is needed that has allowed us to monitor this extraordinary phenomenon," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colo. "Seven years of taking advantage of such opportunities have already made Cassini one of the most scientifically productive planetary missions ever flown."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena manages the mission for the agency's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations team is based at the Space Science Institute in Boulder, Colo. JPL is a division of Caltech.

For more information about the Cassini-Huygens mission, visit and .

Additional view:

Kaleidoscopic rainbows animation:

False-color animation:

Images (mentioned), Text, Credit: NASA / JPL / Jia-Rui Cook.