Category Archives: Gas giants Saturn, Jupiter, et al

Cassini: Cloud bands streak across Saturn’s moon Titan

More good stuff from Cassini as it nears its Grand Finale.

Cassini: The Grand Finale: Cloud Bands Streak Across Titan 

May 9, 2017: NASA’s Cassini spacecraft captured this view of bands of bright, feathery methane clouds drifting across Saturn’s moon Titan on May 7, 2017.

The view was obtained during a distant (non-targeted) flyby, during which Cassini passed 303,000 miles (488,000 kilometers) above the moon’s surface. Although Cassini will have no further close, targeted flybys of Titan, the spacecraft continues to observe the giant moon and its atmosphere from a distance.

The dark regions at top are Titan’s hydrocarbon lakes and seas.

Two versions of this image are presented here, one with stronger enhancement (figure A) and one with much softer enhancement (figure B). See Titan’s Northern Summer Clouds​ for another view of these clouds.

The image was taken on May 7, 2017, at a distance of 316,000 miles (508,000 kilometers). The view is an orthographic projection centered on 57 degrees north latitude, 48 degrees west longitude. An orthographic view is most like the view seen by a distant observer. Image scale is about 2 miles (3 kilometers) per pixel.

As summer approaches in Titan’s northern hemisphere, NASA’s Cassini spacecraft has been monitoring Titan, anticipating an increase in cloud activity at high northern latitudes. [Larger version]
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the 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 operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.

Credit: NASA/JPL-Caltech/Space Science Institute

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Images of Jupiter and the Saturn system

Some great views of two gas giants in our solar system;

** Approaching Jupiter | NASA   

Click for larger version.

This enhanced color view of Jupiter’s south pole was created by citizen scientist Gabriel Fiset using data from the JunoCam instrument on NASA’s Juno spacecraft.  Oval storms dot the cloudscape. Approaching the pole, the organized turbulence of Jupiter’s belts and zones transitions into clusters of unorganized filamentary structures, streams of air that resemble giant tangled strings.

The image was taken on Dec. 11, 2016 at 9:44 a.m. PST (12:44 p.m. EST), from an altitude of about 32,400 miles (52,200 kilometers) above the planet’s beautiful cloud tops.

JunoCam’s raw images are available for the public to peruse and process into image products at: www.missionjuno.swri.edu/junocam

More information about Juno is at: http://www.nasa.gov/juno and http://missionjuno.swri.edu

** Hail the Hexagon | NASA

Click for larger version.

Saturn’s hexagonal polar jet stream is the shining feature of almost every view of the north polar region of Saturn. The region, in shadow for the first part of the Cassini mission, now enjoys full sunlight, which enables Cassini scientists to directly image it in reflected light.

Although the sunlight falling on the north pole of Saturn is enough to allow us to image and study the region, it does not provide much warmth. In addition to being low in the sky (just like summer at Earth’s poles), the sun is nearly ten times as distant from Saturn as from Earth. This results in the sunlight being only about 1 percent as intense as at our planet.

This view looks toward Saturn from about 31 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 22, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers.

The view was obtained at a distance of approximately 560,000 miles (900,000 kilometers) from Saturn. Image scale is 33 miles (54 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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 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 operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and https://www.nasa.gov/cassini. The Cassini imaging team homepage is at https://ciclops.org.

** Cassini: The Grand Finale: Amateur Images – A couple of items from postings by outsider users of NASA raw images

Saturn Mosaic – Ian Regan

Enceladus Over Saturn’s Rings by Sergio Maria-Fagundez

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Video: Cassini films Saturn’s surface during first dive between rings and planet

Images taken by the Cassini spacecraft as it flew between the surface of Saturn and the innermost ring have now been released. The video below starts with the sequence of images of Saturn’s surface and then shows an animation of where the spacecraft was moving and the view that it had of  the planet.

New Movie Shows Cassini’s First Dive over Saturn

As NASA’s Cassini spacecraft made its first-ever dive through the gap between Saturn and its rings on April 26, 2017, one of its imaging cameras took a series of rapid-fire images that were used to make this movie sequence. The video begins with a view of the vortex at Saturn’s north pole, then heads past the outer boundary of the planet’s hexagon-shaped jet stream and continues further southward. Credits: NASA/JPL-Caltech/Space Science Institute/Hampton University See movie sequence 

A new movie sequence of images from NASA’s Cassini spacecraft shows the view as the spacecraft swooped over Saturn during the first of its Grand Finale dives between the planet and its rings on April 26.

The movie comprises one hour of observations as the spacecraft moved southward over Saturn. It begins with a view of the swirling vortex at the planet’s north pole, then heads past the outer boundary of the hexagon-shaped jet stream and beyond.

“I was surprised to see so many sharp edges along the hexagon’s outer boundary and the eye-wall of the polar vortex,” said Kunio Sayanagi, an associate of the Cassini imaging team based at Hampton University in Virginia, who helped produce the new movie. “Something must be keeping different latitudes from mixing to maintain those edges,” he said.

Toward the end of the movie, the camera frame rotates as the spacecraft reorients to point its large, saucer-shaped antenna in the direction of the spacecraft’s motion. The antenna was used as a protective shield during the crossing of Saturn’s ring plane.

As the movie frames were captured, the Cassini spacecraft’s altitude above the clouds dropped from 45,000 to 4,200 miles (72,400 to 6,700 kilometers). As this occurred, the smallest resolvable features in the atmosphere changed from 5.4 miles (8.7 kilometers) per pixel to 0.5 mile (810 meters) per pixel.

“The images from the first pass were great, but we were conservative with the camera settings. We plan to make updates to our observations for a similar opportunity on June 28 that we think will result in even better views,” said Andrew Ingersoll, a member of the Cassini imaging team based at Caltech in Pasadena, California.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency’s Science Mission Directorate in Washington. JPL is a division of the Caltech in Pasadena. The Cassini imaging operations center is based at Space Science Institute in Boulder, Colorado.

For more information about Cassini, visit:

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Video: Cassini flies between Saturn and its rings for first time

The Cassini spacecraft survived its first pass through the gap between Saturn and its rings:

NASA Spacecraft Dives Between Saturn and Its Rings 

NASA’s Cassini spacecraft is back in contact with Earth after its successful first-ever dive through the narrow gap between the planet Saturn and its rings on April 26, 2017. The spacecraft is in the process of beaming back science and engineering data collected during its passage, via NASA’s Deep Space Network Goldstone Complex in California’s Mojave Desert. The DSN acquired Cassini’s signal at 11:56 p.m. PDT on April 26, 2017 (2:56 a.m. EDT on April 27) and data began flowing at 12:01 a.m. PDT (3:01 a.m. EDT) on April 27.

“In the grandest tradition of exploration, NASA’s Cassini spacecraft has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare,”

said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington.

This unprocessed image shows features in Saturn’s atmosphere from closer than ever before. The view was captured by NASA’s Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Credits: NASA/JPL-Caltech/Space Science Institute

As it dove through the gap, Cassini came within about 1,900 miles (3,000 kilometers) of Saturn’s cloud tops (where the air pressure is 1 bar — comparable to the atmospheric pressure of Earth at sea level) and within about 200 miles (300 kilometers) of the innermost visible edge of the rings.

While mission managers were confident Cassini would pass through the gap successfully, they took extra precautions with this first dive, as the region had never been explored.

“No spacecraft has ever been this close to Saturn before. We could only rely on predictions, based on our experience with Saturn’s other rings, of what we thought this gap between the rings and Saturn would be like,” said Cassini Project Manager Earl Maize of NASA’s Jet Propulsion Laboratory in Pasadena, California. “I am delighted to report that Cassini shot through the gap just as we planned and has come out the other side in excellent shape.”

The gap between the rings and the top of Saturn’s atmosphere is about 1,500 miles (2,000 kilometers) wide. The best models for the region suggested that if there were ring particles in the area where Cassini crossed the ring plane, they would be tiny, on the scale of smoke particles. The spacecraft zipped through this region at speeds of about 77,000 mph (124,000 kph) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the spacecraft.

This unprocessed image shows features in Saturn’s atmosphere from closer than ever before. The view was captured by NASA’s Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Credits: NASA/JPL-Caltech/Space Science Institute

As a protective measure, the spacecraft used its large, dish-shaped high-gain antenna (13 feet or 4 meters across) as a shield, orienting it in the direction of oncoming ring particles. This meant that the spacecraft was out of contact with Earth during the ring-plane crossing, which took place at 2 a.m. PDT (5 a.m. EDT) on April 26. Cassini was programmed to collect science data while close to the planet and turn toward Earth to make contact about 20 hours after the crossing.

Cassini’s next dive through the gap is scheduled for May 2.

This unprocessed image shows features in Saturn’s atmosphere from closer than ever before. The view was captured by NASA’s Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Credits: NASA/JPL-Caltech/Space Science Institute

Launched in 1997, Cassini arrived at Saturn in 2004. Following its last close flyby of the large moon Titan on April 21 PDT (April 22 EDT), Cassini began what mission planners are calling its “Grand Finale.” During this final chapter, Cassini loops Saturn approximately once per week, making a total of 22 dives between the rings and the planet. Data from this first dive will help engineers understand if and how they will need to protect the spacecraft on its future ring-plane crossings. The spacecraft is on a trajectory that will eventually plunge into Saturn’s atmosphere — and end Cassini’s mission — on Sept. 15, 2017.

More information about Cassini’s Grand Finale, including images and video, is available at:

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL, a division of Caltech in Pasadena, California, manages the mission for NASA’s Science Mission Directorate. JPL designed, developed and assembled the Cassini orbiter.

More information about Cassini is at:

Video: A 360-degree view of Cassini diving between Saturn and the rings

This interactive video from NASA JPL allows you to scan Saturn and the rings as the Cassini spacecraft makes one of its dives between the two before the Grand Finale in September.

Dive between Saturn and its rings with NASA’s Cassini spacecraft in the final chapter of its mission. In this 360-degree video, you are traveling along with the spacecraft at tens of thousands of miles per hour as it makes one of 22 planned dives through this unexplored gap. The first dive of Cassini’s Grand Finale takes place on April 26, 2017, with additional dives about once a week. 

Key Dates
  • April 22: Titan 126 Flyby at 6:08 a.m. UTC (11:08 p.m. PDT on April 21)
  • April 23: First Grand Finale Orbit Begins at 3:46 a.m. UTC (8:46 p.m. PDT on April 22)
  • April 26: First Ringplane Crossing at 9 a.m. UTC (2 a.m. PDT)
  • May 24: Northern Summer Solstice Begins
  • Sept. 15: Cassini’s Final Entry into Saturn’s Atmosphere begins at 10:44 a.m. UTC (3:44 a.m. PDT). Spacecraft loss of signal comes one minute later at 10:45 a.m. UTC (3:45 a.m. PDT).
  • Sept. 15: Final signal received on Earth at 12:08 p.m. UTC (5:08 a.m. PDT)

See also these other recent Cassini posts:

Here is a view of Earth and the Moon as seen recently by Cassini through the rings: NASA Image Shows Earth Between the Rings of Saturn | NASA

This cropped, zoomed-in version of the image makes it easier to see Earth’s moon — a smaller, fainter dot to the left of our planet’s bright dot. Credits: NASA/JPL-Caltech/Space Science Institute Full image and caption

Here is a new video of Saturn’s hexagon north pole using Cassini images: Cassini: Mission to Saturn: Saturn’s Hexagon in Motion

North pole of Saturn made from Cassini images. Different wavelengths of light from ultraviolet to visible to infrared have been assigned colors.

The gray scale version:

The black and white version.

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