posted March 09, 2006 12:15 PM               

NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt in Yellowstone-like geysers on Saturn's moon Enceladus. The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon.

"We realize that this is a radical conclusion - that we may have evidence for liquid water within a body so small and so cold," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute, Boulder, Colo. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."

posted March 09, 2006 12:19 PM               

NASA's Cassini Discovers Potential Liquid Water on Enceladus

NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt in Yellowstone-like geysers on Saturn's moon Enceladus. The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon.

"We realize that this is a radical conclusion - that we may have evidence for liquid water within a body so small and so cold," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute, Boulder, Colo. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."

High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed. Scientists examined several models to explain the process. They ruled out the idea the particles are produced or blown off the moon's surface by vapor created when warm water ice converts to a gas. Instead, scientists have found evidence for a much more exciting possibility. The jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser in Yellowstone.

"We previously knew of at most three places where active volcanism exists: Jupiter's moon Io, Earth, and possibly Neptune's moon Triton. Cassini changed all that, making Enceladus the latest member of this very exclusive club, and one of the most exciting places in the solar system," said John Spencer, Cassini scientist, Southwest Research Institute, Boulder.

"Other moons in the solar system have liquid-water oceans covered by kilometers of icy crust," said Andrew Ingersoll, imaging team member and atmospheric scientist at the California Institute of Technology, Pasadena, Calif. "What's different here is that pockets of liquid water may be no more than tens of meters below the surface."

"As Cassini approached Saturn, we discovered the Saturnian system is filled with oxygen atoms. At the time we had no idea where the oxygen was coming from," said Candy Hansen, Cassini scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena. "Now we know Enceladus is spewing out water molecules, which break down into oxygen and hydrogen."

Scientists still have many questions. Why is Enceladus so active? Are other sites on Enceladus active? Might this activity have been continuous enough over the moon's history for life to have had a chance to take hold in the moon's interior?

In the spring of 2008, scientists will get another chance to look at Enceladus when Cassini flies within 350 kilometers (approximately 220 miles), but much work remains after the spacecraft's four-year prime mission is over.

"There's no question, along with the moon Titan, Enceladus should be a very high priority for us. Saturn has given us two exciting worlds to explore," said Jonathan Lunine, Cassini interdisciplinary scientist, University of Arizona, Tucson, Ariz.

Mission scientists report these and other Enceladus findings in this week's issue of Science. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.

JPL, a division of the California Institute of Technology, manages the Cassini-Huygens mission for NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL.

posted May 04, 2006 11:55 PM               

This movie, built with data collected during the European Space Agency's Huygens probe on Jan. 14, 2005, shows the operation of the Descent Imager/Spectral Radiometer camera during its descent and after touchdown. The camera was funded by NASA.

The almost four-hour-long operation of the camera is shown in less than five minutes. That's 40 times the actual speed up to landing and 100 times the actual speed thereafter.

The first part of the movie shows how Titan looked to the camera as it acquired more and more images during the probe's descent. Each image has a small field of view, and dozens of images were made into mosaics of the whole scene...

Sounds from a left speaker trace Huygens' motion, with tones changing with rotational speed and the tilt of the parachute. There also are clicks that clock the rotational counter, as well as sounds for the probe's heat shield hitting Titan's atmosphere, parachute deployments, heat shield release, jettison of the camera cover and touchdown.

Sounds from a right speaker go with the Descent Imager/Spectral Radiometer activity. There's a continuous tone that represents the strength of Huygens' signal to Cassini. Then there are 13 different chimes - one for each of instrument's 13 different science parts - that keep time with flashing-white-dot exposure counters. During its descent, the Descent Imager/Spectral Radiometer took 3,500 exposures.

posted May 05, 2006 03:08 AM            

Also, watching the parachute animation - especially at beginning of sequence where the reefing lines are really 'blown' about by the upper atmosphere winds (?) on Titan.

The parachutes moves about quite a bit lower down during sequence.

posted May 05, 2006 10:58 AM               

quote:

---

Originally posted by Robert Pearlman:
I haven't been able to find a higher resolution of the above movie yet, but coming in a close second on the "cool-o-meter" is this music video (The View from Huygens, 70 mb) which plays the same imagery but with a different perspective and a much larger size.

---

posted October 12, 2006 02:23 AM               

quote:

---

Originally posted by dss65:
Magnificent. Who needs fantasy when reality offers this?

---

posted November 08, 2006 07:35 AM               

The Cassini spacecraft is roughly halfway through its looping voyage of the Saturn system and is continuing to return a bounty of data on the ringed planet and its moons. Yet all journeys must have an end and Cassini's eventual fate is now being discussed.

"Current planning is for a two year mission extension that ends on July 1, 2010," said Robert Mitchell, NASA's Cassini mission program manager. "However, presuming that the spacecraft continues to function well, it's reasonable to expect that one or more further extensions will be supported."

Sometime around 2012, Cassini, like the ocean-going ships of old, will need to be decommissioned. However, the spacecraft cannot be towed to some nearby shore to be dismantled; she must either drop anchor, be scuttled, or cast off her gravitational moorings altogether.

posted September 12, 2007 07:56 PM               

The international Cassini spacecraft went into safe mode this week after successfully passing over a Saturn moon that was the mysterious destination of a deep-space faring astronaut in Arthur C. Clarke's novel "2001: A Space Odyssey."

Cassini flew within 1,000 miles (1609 kilometers) of Iapetus on Monday and took images of its rugged, two-toned surface. As it was sending data back to Earth, it was hit by a cosmic ray that caused a power trip. The spacecraft was not damaged, but had to turn off its instruments and relay only limited information.

Mission controllers have since sent commands for Cassini to resume normal transmission, and scientists recovered all the data from the moon flyby despite a nearly 12-hour delay. The spacecraft was expected to be fully functional by week's end.

posted October 15, 2007 07:59 PM               

Ten years ago today, NASA's Cassini spacecraft departed planet Earth from Cape Canaveral, Florida, and embarked on a seven-year long, circuitous journey of several billion miles across the solar system to the planet Saturn.

To celebrate this special occasion, the mission's imaging team is releasing today a spate of captivating new images and movies of the ringed planet and some of its most photogenic companions.

Headlining this bounty are two expansive and stunning natural color mosaics of Saturn and its rings. One of these is the view seen by the spacecraft as it looked back towards Saturn from its close encounter with the moon Iapetus last month, and shows the shadow-draped planet surrounded by its rings and many of its major icy moons. Another view peers down onto the planet's swirling blue and gold clouds and its splendid rings from a vantage point high above Saturn's equator.

Along with several other colorful views of the planet, there are dramatic vistas (including one stereo image, or anaglyph) of the cratered faces of a few of the planet's icy moons, a high resolution survey of the main ring system in natural color, colorful glimpses of Titan and an updated black-and-white map of Titan's surface.

Two exciting movies from Cassini also make their debut today. One sequence shows the detailed motions of the F-ring as its shepherd moon Prometheus approaches the ring, draws material from it, and gouges a channel in the dust-sized material remaining there.

But by far the most thrilling offering of all is a breathtaking flyover movie of the awesome 10-kilometer (6-mile) high equatorial ridge on Iapetus, acquired when Cassini was only a few thousand kilometers about the surface.

Imaging team leader Carolyn Porco at CICLOPS in Boulder, Colo. said, "To the thousands upon thousands of fellow explorers who have traveled along with us since we departed Earth 10 years ago today, who have followed our adventures across the solar system and into orbit around Saturn and who have since been as awestruck as we have at our findings there, we say, 'Happy Anniversary! It's been a pleasure flying with you.'"

The new images and movies are available at www.ciclops.org, www.nasa.gov/cassini and saturn.jpl.nasa.gov.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the U.S., England, France, and Germany. The imaging operations center and team leader (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

posted February 01, 2008 09:59 AM               

Journey to Saturn From Your Computer

Want a peek at Saturn as seen from space? A new interactive 3-D viewer that uses a game engine and allows users to travel to Saturn and see it the way the Cassini spacecraft sees it is now online.

The Cassini at Saturn Interactive Explorer makes the real Cassini mission data fully available in three colorful, easy-to-use expeditions.

The "Where is Cassini Now?" expedition shows exactly where the Cassini spacecraft is and what it is doing each moment over the current 24-hour period. Viewers can see the spacecraft move in its orbit and maneuver according to instructions from mission scientists and navigators at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

With the "Mission Overview" expedition, look back in time as Cassini orbited the Saturn system over the past 3.5 years, and fast-forward into the future to see where it is headed. Users can control two virtual cameras to see Cassini fly by Saturn and its moons.

The "Saturn's Moons" expedition gives an in-depth peek at seven of Saturn's moons, providing useful facts and interactive surface views of each one.

posted March 14, 2008 02:08 AM               

A software malfunction prevented a key piece of equipment on the Cassini spacecraft from recording data as it flew through the plume from a geyser shooting off a moon of Saturn, NASA said late on Thursday.

NASA called the problem "an unexplained software hiccup" that came at a very bad time, preventing Cassini's Cosmic Dust Analyzer instrument from collecting data for about two hours as it flew over the surface of the moon Enceladus on Wednesday.

A key objective of the fly-by was to determine the density, size, composition and speed of particles erupting into space from the moon's south pole in a dramatic plume.

Bob Mitchell, Cassini program manager, said the problem meant that the instrument did not collect data as the craft flew through the plume -- a process lasting under a minute.

posted March 20, 2008 05:35 PM               

quote:

---

Originally posted by Blackarrow:
Did this software malfunction affect image gathering?

---

NASA to Release New Details From Close Flyby of Saturn Moon

NASA will hold a news conference at 2 p.m. EDT, Wednesday, March 26, to present new clues on the composition of the icy plumes jetting off the surface of Saturn's moon Enceladus. The findings were obtained March 12 during the closest flyby of the moon by the Cassini spacecraft.

Participants in the press conference will be:

• Hunter Waite, Southwest Research Institute, San Antonio, principal investigator, Ion and Neutral Mass Spectrometer
  
• John Spencer, Southwest Research Institute, Boulder, Colo., co-investigator, Composite Infrared Spectrometer
  
• Larry Esposito, University of Colorado, Boulder, principal investigator, Ultraviolet Imaging Spectrograph
  
• Carolyn Porco, Space Science Institute, Boulder, team leader, Imaging Science Subsystem

posted March 20, 2008 05:52 PM               

NASA's Cassini spacecraft has discovered evidence that points to the existence of an underground ocean of water and ammonia on Saturn's moon Titan. The findings made using radar measurements of Titan's rotation will appear in the March 21 issue of the journal Science.

"With its organic dunes, lakes, channels and mountains, Titan has one of the most varied, active and Earth-like surfaces in the solar system," said Ralph Lorenz, lead author of the paper and Cassini radar scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., "Now we see changes in the way Titan rotates, giving us a window into Titan's interior beneath the surface."

Members of the mission's science team used Cassini's Synthetic Aperture Radar to collect imaging data during 19 separate passes over Titan between October 2005 and May 2007. The radar can see through Titan's dense, methane-rich atmospheric haze, detailing never-before-seen surface features and establishing their locations on the moon's surface.

Using data from the radar's early observations, the scientists and radar engineers established the locations of 50 unique landmarks on Titan's surface. They then searched for these same lakes, canyons and mountains in the reams of data returned by Cassini in its later flybys of Titan. They found prominent surface features had shifted from their expected positions by up to 19 miles. A systematic displacement of surface features would be difficult to explain unless the moon's icy crust was decoupled from its core by an internal ocean, making it easier for the crust to move.

"We believe that about 62 miles beneath the ice and organic-rich surface is an internal ocean of liquid water mixed with ammonia," said Bryan Stiles of NASA's Jet Propulsion Laboratory (JPL) in, Pasadena, Calif. Stiles also is a contributing author to the paper.

The study of Titan is a major goal of the Cassini-Huygens mission because it may preserve, in deep-freeze, many of the chemical compounds that preceded life on Earth. Titan is the only moon in the solar system that possesses a dense atmosphere. The moon's atmosphere is 1.5 times denser than Earth's. Titan is the largest of Saturn's moons, bigger than the planet Mercury.

"The combination of an organic-rich environment and liquid water is very appealing to astrobiologists," Lorenz said. "Further study of Titan's rotation will let us understand the watery interior better, and because the spin of the crust and the winds in the atmosphere are linked, we might see seasonal variation in the spin in the next few years."

Cassini scientists will not have long to wait before another go at Titan. On March 25, just prior to its closest approach at an altitude of 620 miles, Cassini will employ its Ion and Neutral Mass Spectrometer to examine Titan's upper atmosphere. Immediately after closest approach, the spacecraft's Visual and Infrared Mapping Spectrometer will capture high-resolution images of Titan's southeast quadrant.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The mission is managed by JPL, a division of the California Institute of Technology in Pasadena. The Cassini orbiter also was designed, developed and assembled at JPL.

posted April 16, 2008 11:01 AM               

NASA Extends Cassini's Grand Tour of Saturn

NASA is extending the international Cassini-Huygens mission by two years. The historic spacecraft's stunning discoveries and images have revolutionized our knowledge of Saturn and its moons.

Cassini's mission originally had been scheduled to end in July 2008. The newly-announced two-year extension will include 60 additional orbits of Saturn and more flybys of its exotic moons. These will include 26 flybys of Titan, seven of Enceladus, and one each of Dione, Rhea and Helene. The extension also includes studies of Saturn's rings, its complex magnetosphere, and the planet itself.

"This extension is not only exciting for the science community, but for the world to continue to share in unlocking Saturn's secrets," said Jim Green, director, Planetary Science Division, NASA Headquarters, Washington. "New discoveries are the hallmarks of its success, along with the breathtaking images beamed back to Earth that are simply mesmerizing."

"The spacecraft is performing exceptionally well and the team is highly motivated, so we're excited at the prospect of another two years," said Bob Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Based on findings from Cassini, scientists think liquid water may be just beneath the surface of Saturn's moon, Enceladus. That's why the small moon, only one-tenth the size of Titan and one-seventh the size of Earth's moon, is one of the highest-priority targets for the extended mission.

Cassini discovered geysers of water-ice jetting from the Enceladus' surface. The geysers, which shoot out at a distance three times the diameter of Enceladus, feed particles into Saturn's most expansive ring. In the extended mission, the spacecraft may come as close as 15 miles from the moon's surface.

Cassini's observations of Saturn's largest moon, Titan, have given scientists a glimpse of what Earth might have been like before life evolved. They now believe Titan possesses many parallels to Earth, including lakes, rivers, channels, dunes, rain, snow, clouds, mountains and possibly volcanoes.

"When we designed the original tour, we really did not know what we would find, especially at Enceladus and Titan," said Dennis Matson, the JPL Cassini project scientist. "This extended tour is responding to these new discoveries and giving us a chance to look for more."

Unlike Earth, Titan's lakes, rivers and rain are composed of methane and ethane, and temperatures reach a chilly minus 290 degrees Fahrenheit. Although Titan's dense atmosphere limits viewing the surface, Cassini's high-resolution radar coverage and imaging by the infrared spectrometer have given scientists a better look.

Other activities for Cassini scientists will include monitoring seasons on Titan and Saturn, observing unique ring events, such as the 2009 equinox when the sun will be in the plane of the rings, and exploring new places within Saturn's magnetosphere.

Cassini has returned a daily stream of data from Saturn's system for almost four years. Its travel scrapbook includes nearly 140,000 images and information gathered during 62 revolutions around Saturn, 43 flybys of Titan and 12 close flybys of the icy moons.

More than 10 years after launch and almost four years after entering into orbit around Saturn, Cassini is a healthy and robust spacecraft. Three of its science instruments have minor ailments, but the impact on science-gathering is minimal. The spacecraft will have enough propellant left after the extended mission to potentially allow a third phase of operations. Data from the extended mission could lay the groundwork for possible new missions to Titan and Enceladus.

Cassini launched Oct. 15, 1997, from Cape Canaveral, Fla., on a seven-year journey to Saturn, traversing 2.2 billion miles. It is one of the most scientifically capable spacecraft ever launched, with a record 12 instruments on the orbiter and six more instruments on the European Space Agency's Huygens probe, which piggybacked a ride to Titan on Cassini. Cassini receives electrical power from three radioisotope thermoelectric generators, which generate electricity from heat produced by the natural decay of plutonium. The spacecraft was captured into Saturn orbit in June 2004 and immediately began returning data to Earth.

The Cassini-Huygens mission is a cooperative project between NASA, the European Space Agency and the Italian Space Agency.