SUN GLINTS OFF TITAN'S POLAR SEAS

FROM:  NASA 

This near-infrared, color mosaic from NASA's Cassini spacecraft shows the sun glinting off of Titan's north polar seas. While Cassini has captured, separately, views of the polar seas (see PIA17470) and the sun glinting off of them (see PIA12481 and PIA18433) in the past, this is the first time both have been seen together in the same view. The sunglint, also called a specular reflection, is the bright area near the 11 o'clock position at upper left. This mirror-like reflection, known as the specular point, is in the south of Titan's largest sea, Kraken Mare, just north of an island archipelago separating two separate parts of the sea. This particular sunglint was so bright as to saturate the detector of Cassini's Visual and Infrared Mapping Spectrometer (VIMS) instrument, which captures the view. It is also the sunglint seen with the highest observation elevation so far -- the sun was a full 40 degrees above the horizon as seen from Kraken Mare at this time -- much higher than the 22 degrees seen in PIA18433. Because it was so bright, this glint was visible through the haze at much lower wavelengths than before, down to 1.3 microns. The southern portion of Kraken Mare (the area surrounding the specular feature toward upper left) displays a "bathtub ring" -- a bright margin of evaporate deposits -- which indicates that the sea was larger at some point in the past and has become smaller due to evaporation. The deposits are material left behind after the methane & ethane liquid evaporates, somewhat akin to the saline crust on a salt flat. The highest resolution data from this flyby -- the area seen immediately to the right of the sunglint -- cover the labyrinth of channels that connect Kraken Mare to another large sea, Ligeia Mare. Ligeia Mare itself is partially covered in its northern reaches by a bright, arrow-shaped complex of clouds. The clouds are made of liquid methane droplets, and could be actively refilling the lakes with rainfall. The view was acquired during Cassini's August 21, 2014, flyby of Titan, also referred to as "T104" by the Cassini team. The view contains real color information, although it is not the natural color the human eye would see. Here, red in the image corresponds to 5.0 microns, green to 2.0 microns, and blue to 1.3 microns. These wavelengths correspond to atmospheric windows through which Titan's surface is visible. The unaided human eye would see nothing but haze, as in PIA12528. 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, Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The VIMS team is based at the University of Arizona in Tucson.  Image Credit: NASA/JPL-Caltech/University of Arizona/University of Idaho.

MIMAS, THE "DEATH STAR" MOON

FROM:  NASA

A thin sliver of Mimas is illuminated, the long shadows showing off its many craters, indicators of the moon's violent history. The most famous evidence of a collision on Mimas (246 miles, or 396 kilometers across) is the crater Herschel that gives Mimas its Death Star-like appearance.  North on Mimas is up and rotated 40 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 20, 2013. The view was acquired at a distance of approximately 100,000 miles (200,000 kilometers) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 130 degrees. Image scale is 4,000 feet (1 kilometer) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, 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, D.C. 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, Colo.  Credit: NASA/JPL-Caltech/Space Science Institute.

WATER UNDER ENCELADUS

FROM:  NASA 

Ocean Inside Saturn's Moon Enceladus

This diagram illustrates the possible interior of Saturn's moon Enceladus based on a gravity investigation by NASA's Cassini spacecraft and NASA's Deep Space Network, reported in April 2014. The gravity measurements suggest an ice outer shell and a low density, rocky core with a regional water ocean sandwiched in between at high southern latitudes.

Views from Cassini's imaging science subsystem were used to depict the surface geology of Enceladus and the plume of water jets gushing from fractures near the moon's south pole.

Enceladus is 313 miles (504 kilometers) in diameter.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.
Image Credit: NASA/JPL-Caltech.

TINY TETHYS OF SATURN

FROM: NASATethys may not be tiny by normal standards, but when it is captured alongside Saturn, it can't help but seem pretty small.

Even Saturn's rings appear to dwarf Tethys (660 miles, or 1,062 kilometers across), which is in the upper left of the image, although scientists believe the moon to be many times more massive than the entire ring system combined. This view looks toward the unilluminated side of the rings from about 18 degrees below the ringplane. The image was taken in green light with the Cassini spacecraft wide-angle camera on Aug. 19, 2012.

The view was acquired at a distance of approximately 1.5 million miles (2.4 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 63 degrees. Image scale is 86 miles (138 kilometers) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, 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, D.C. 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, Colo.

Image credit-NASA-JPL-Caltech-Space Science Institute

CASSINI SPACECRAFT SEES NEW OBJECTS BLAZING TRAILS IN SATURN RING

FROM:  NASA
WASHINGTON -- Scientists working with images from NASA's Cassini
spacecraft have discovered strange, half-mile-sized objects punching
through one of Saturn's rings and leaving glittering trails behind
them. The results will be presented tomorrow at the European
Geosciences Union meeting in Vienna, Austria.

The penetration occurred in the outermost of Saturn's main rings,
called the F ring, which has a circumference of 550,000 miles
(881,000 kilometers). Scientists are calling the trails in the F ring
"mini-jets." Cassini scientists combed through 20,000 images and
found 500 examples of these rogues during the seven years Cassini has
been at Saturn.

"Beyond just showing us the strange beauty of the F ring, Cassini's
studies of this ring help us understand the activity that occurs when
solar systems evolve out of dusty disks that are similar to, but
obviously much grander than, the disk we see around Saturn," said
Linda Spilker, Cassini project scientist at NASA's Jet Propulsion
Laboratory (JPL) in Pasadena, Calif.

Scientists have known relatively large objects can create channels,
ripples and snowballs, or clumps of icy material, in the F ring.
However, scientists did not know what happened to these snowballs
after they were created. Some were broken up by collisions or tidal
forces in their orbit around Saturn. Scientists now have evidence
some of the smaller ones survived, and their differing orbits mean
they go on to strike through the F ring on their own.

"I think the F ring is Saturn's weirdest ring, and these latest
Cassini results go to show how the F ring is even more dynamic than
we ever thought," said Carl Murray, a Cassini imaging team member
based at Queen Mary University of London, U.K. "These findings show
us that the F ring region is like a bustling zoo of objects from a
half-mile (0.8-kilometer) in size to moons like Prometheus a hundred
miles (160.9 kilometers) in size, creating a spectacular show."

These small objects appear to collide with the F ring at gentle speeds
about 4 mph (2 meters per second). The collisions drag glittering ice
particles out of the F ring with them, leaving a trail of 20-110
miles (40-180 kilometers) long.

In some cases, the objects traveled in packs, creating mini-jets that
looked exotic, like the barb of a harpoon. Other new images show
grand views of the entire F ring and the swirls and eddies from the
different kinds of objects moving through and around it.

Saturn's rings are comprised primarily of water ice. The chunks of ice
that make up the main rings spread out 85,000 miles (140,000
kilometers) from the center of Saturn. Scientists believe the rings'
average thickness is approximately 30 feet (10 meters).

The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the Italian Space Agency. JPL manages the
mission for NASA's Science Mission Directorate in Washington. The
imaging team is based at the Space Science Institute in Boulder,
Colo.