A giant of a moon appears before a giant of a planet undergoing seasonal changes in this natural color view of Titan and Saturn from NASA’s Cassini spacecraft.
Titan, Saturn’s largest moon, measures 3,200 miles, or 5,150 kilometers, across and is larger than the planet Mercury. Cassini scientists have been watching the moon’s south pole since a vortex appeared in its atmosphere in 2012. See PIA14919 and PIA14920 to learn more about this mass of swirling gas around the pole in the atmosphere of the moon.
As the seasons have changed in the Saturnian system, and spring has come to the north and autumn to the south, the azure blue in the northern Saturnian hemisphere that greeted Cassini upon its arrival in 2004 is now fading. The southern hemisphere, in its approach to winter, is taking on a bluish hue. This change is likely due to the reduced intensity of ultraviolet light and the haze it produces in the hemisphere approaching winter, and the increasing intensity of ultraviolet light and haze production in the hemisphere approaching summer. (The presence of the ring shadow in the winter hemisphere enhances this effect.) The reduction of haze and the consequent clearing of the atmosphere makes for a bluish hue: the increased opportunity for direct scattering of sunlight by the molecules in the air makes the sky blue, as on Earth. The presence of methane, which generally absorbs in the red part of the spectrum, in a now clearer atmosphere also enhances the blue.
This view looks toward the northern, sunlit side of the rings from just above the ring plane.
This mosaic combines six images — two each of red, green and blue spectral filters — to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on May 6, 2012, at a distance of approximately 483,000 miles (778,000 kilometers) from Titan. Image scale is 29 miles (46 kilometers) per pixel on Titan.
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/SSI
The Cassini spacecraft watches a pair of Saturn’s moons, showing the hazy orb of giant Titan beyond smaller Tethys. This view looks toward the Saturn-facing sides of Titan (3,200 miles, or 5,150 kilometers across) and Tethys (660 miles, or 1,062 kilometers across).
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Oct. 18, 2010. The view was obtained at a distance of approximately 1.6 million miles (2.5 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 55 degrees. The view was obtained at a distance of approximately 930,000 miles (1.5 million kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 55 degrees. Image scale is 15 kilometers (9 miles) per pixel on Titan and 6 miles (9 kilometers) per pixel on Tethys.
Image Credit: NASA/JPL/Space Science Institute
Humanity’s robot orbiting Saturn has recorded yet another amazing view. That robot, of course, is the spacecraft Cassini, while the new amazing view includes a bright moon, thin rings, oddly broken clouds, and warped shadows. Titan, Saturn’s largest moon, appears above as a featureless tan as it is continually shrouded in thick clouds. The rings of Saturn are seen as a thin line because they are so flat and imaged nearly edge on. Details of Saturn’s rings are therefore best visible in the dark ring shadows seen across the giant planet’s cloud tops. Since the ring particles orbit in the same plane as Titan, they appear to skewer the foreground moon. In the upper hemisphere of Saturn, the clouds show many details, including dips in long bright bands indicating disturbances in a high altitude jet stream. Recent precise measurements of how much Titan flexes as it orbits Saturn hint that vast oceans of water might exist deep underground.
Image Credit: NASA/JPL-Caltech/Space Science Institute/J. Major
This artist’s concept shows a possible scenario for the internal structure of Titan, as suggested by data from NASA’s Cassini spacecraft. Scientists have been trying to determine what is under Titan’s organic-rich atmosphere and icy crust. Data from the radio science experiment make the strongest case yet for a global subsurface ocean, sitting above a subsurface layer of high-pressure ice and a water-infused silicate core.
Data from NASA’s Cassini spacecraft have revealed Saturn’s moon Titan likely harbors a layer of liquid water under its ice shell.
Researchers saw a large amount of squeezing and stretching as the moon orbited Saturn. They deduced that if Titan were composed entirely of stiff rock, the gravitational attraction of Saturn would cause bulges, or solid “tides,” on the moon only 3 feet (1 meter) in height. Spacecraft data show Saturn creates solid tides approximately 30 feet (10 meters) in height, which suggests Titan is not made entirely of solid rocky material. The finding appears in today’s edition of the journal Science.
I hope to download the paper(1) tomorrow…
For now the abstract:
We have detected in Cassini data the signature of the periodic tidal stresses within Titan driven by the eccentricity (e = 0.028) of its 16-day orbit around Saturn. Precise measurements of the acceleration of the Cassini spacecraft during six close flybys between 2006 and 2011 have revealed that Titan responds to the variable tidal field exerted by Saturn with periodic changes of its quadrupole gravity, at about 4% of the static value. Two independent determinations of the corresponding degree-2 Love number yield k2 = 0.589 ± 0.150 and k2 = 0.637 ± 0.224 (2σ). Such a large response to the tidal field requires that Titan’s interior is deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth.
(1) Luciano Iess, Robert A. Jacobson, Marco Ducci, David J. Stevenson, Jonathan I. Lunine, John W. Armstrong, Sami W. Asmar, Paolo Racioppa, Nicole J. Rappaport, Paolo Tortora (2012). The Tides of Titan Science Express DOI: 10.1126/science.1219631
Image credit: A. Tavani | An animation
Known for its bright ring system and many moons, gas giant Saturn looks strange and unfamiliar in this false-color view from the Cassini spacecraft. In fact, in this Visual and Infrared Mapping Spectrometer (VIMS) mosaic the famous rings are almost invisible, seen edge-on cutting across picture center. The most striking contrast in the image is along the terminator or boundary between night and day. To the right (day side) blue-green hues are visible sunlight reflected from Saturn’s cloud tops. But on the left (night side) in the absence of sunlight, the lantern-like glow of infrared radiation from the planet’s warm interior silhouettes features at Saturn’s deeper cloud levels. The infrared glow also shines from the broad shadows of Saturn’s rings sweeping across the planet’s upper hemisphere.
Credit: VIMS Team, U. Arizona, ESA, NASA
Even in a peaceful looking scene such as this one of Saturn and its moon Tethys, the Cassini spacecraft reveals clues about how Saturn is ever-changing. Saturn’s northern hemisphere still shows the scars of the huge storm that raged through much of 2011 (see PIA14905). And, day by day, the shadows cast by the rings on the planet’s southern hemisphere are growing wider as the seasons progress toward northern summer. See PIA11667 and PIA09793 to learn about the changing seasons and the shadows cast by the rings.Image Credit: NASA/JPL-Caltech/Space Science Institute
Tethys (660 miles, or 1,062 kilometers across) appears above the rings to the left of the center of the image.
The image was taken with the Cassini spacecraft wide-angle camera on Jan. 10, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 39 degrees. Image scale on Saturn is 84 miles (136 kilometers) per pixel.
A brightly reflective Enceladus appears before Saturn’s rings, while the planet’s larger moon Titan looms in the distance.
Jets of water ice and vapor emanating from the south pole of Enceladus, which hint at subsurface sea rich in organics, and liquid hydrocarbons ponding on the surface on the surface of Titan make these two of the most fascinating moons in the Saturnian system.
Enceladus (313 miles, or 504 kilometers across) is in the center of the image. Titan (3,200 miles, or 5,150 kilometers across) glows faintly in the background beyond the rings. This view looks toward the anti-Saturn side of Enceladus and the Saturn-facing side of Titan. The northern, sunlit side of the rings is seen from just above the ringplane.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on March 12, 2012. The view was acquired at a distance of approximately 600,000 miles (1 million kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 36 degrees. Image scale is 4 miles (6 kilometers) per pixel on Enceladus.
Image credit: NASA/JPL-Caltech/Space Science Institute
This false-color image shows evidence for lakes of liquid hydrocarbons, probably methane or ethane, on Titan’s surface. The lakes are represented as dark areas, but are not what the human eye would see, because radar was used to penetrate the thick haze obscuring Titan’s surface. The Cassini radar instrument acquired this image on July 22, 2006. The image is centered near 80 degrees north, 35 degrees west and is about 140 kilometers (84 miles) across. The strip of radar imagery is foreshortened to simulate an oblique view of the highest latitude region, seen from a point to its west. Smallest details in this image are about 500 meters (1,640 feet) across.Credit: NASA/JPL/USGS
Phoebe’s true nature is revealed in startling clarity in this mosaic of two images taken during Cassini’s flyby on June 11, 2004. The image shows evidence for the emerging view that Phoebe may be an ice-rich body coated with a thin layer of dark material. Small bright craters in the image are probably fairly young features. This phenomenon has been observed on other icy satellites, such as Ganymede at Jupiter. When impactors slammed into the surface of Phoebe, the collisions excavated fresh, bright material — probably ice — underlying the surface layer. Further evidence for this can be seen on some crater walls where the darker material appears to have slid downwards, exposing more light-colored material. Some areas of the image that are particularly bright - especially near lower right - are over-exposed.Image credit: NASA/JPL-Caltech/Space Science Institute
An accurate determination of Phoebe’s density — a forthcoming result from the flyby — will help Cassini mission scientists understand how much of the little moon is comprised of ices.
This spectacular view was obtained at a phase, or Sun-Phoebe-spacecraft, angle of 84 degrees, and from a distance of approximately 32,500 kilometers (20,200 miles). The image scale is approximately 190 meters (624 feet) per pixel. No enhancement was performed on this image.
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 Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
Images from NASA’s Cassini spacecraft have revealed half-mile-sized (kilometer-sized) objects punching through parts of Saturn’s F ring, leaving glittering trails behind them. These trails in the rings, which scientists are calling “mini-jets,” fill in a missing link in our story of the curious behavior of the F ring.