NASA’s Cassini spacecraft has begun returning its best-ever views of the northern extremes of Saturn’s icy, ocean-bearing moon Enceladus. The spacecraft obtained the images during its Oct. 14 flyby, passing 1,142 miles (1,839 kilometers) above the moon’s surface. Mission controllers say the spacecraft will continue transmitting images and other data from the encounter for the next several days.
A Fractured Pole October 15, 2015 Full-Res: PIA19660 NASA’s Cassini spacecraft zoomed by Saturn’s icy moon Enceladus on Oct. 14, 2015, capturing this stunning image of the moon’s north pole. A companion view from the wide-angle camera (PIA20010) shows a zoomed out view of the same region for context. Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but high-resolution Cassini images show a landscape of stark contrasts. Thin cracks cross over the pole — the northernmost extent of a global system of such fractures. Before this Cassini flyby, scientists did not know if the fractures extended so far north on Enceladus. North on Enceladus is up…. ContinueScientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but the new high-resolution Cassini images show a landscape of stark contrasts. “The northern regions are crisscrossed by a spidery network of gossamer-thin cracks that slice through the craters,” said Paul Helfenstein, a member of the Cassini imaging team at Cornell University, Ithaca, New York. “These thin cracks are ubiquitous on Enceladus, and now we see that they extend across the northern terrains as well.”
In addition to the processed images, unprocessed, or “raw,” images are posted on the Cassini mission website at:
Cassini’s next encounter with Enceladus is planned for Oct. 28, when the spacecraft will come within 30 miles (49 kilometers) of the moon’s south polar region. During the encounter, Cassini will make its deepest-ever dive through the moon’s plume of icy spray, sampling the chemistry of the extraterrestrial ocean beneath the ice. Mission scientists are hopeful data from that flyby will provide evidence of how much hydrothermal activity is occurring in the moon’s ocean, along with more detailed insights about the ocean’s chemistry — both of which relate to the potential habitability of Enceladus.
NASA’s Cassini spacecraft spied this tight trio of craters as it approached Saturn’s icy moon Enceladus for a close flyby on Oct. 14, 2015. The craters, located at high northern latitudes, are sliced through by thin fractures — part of a network of similar cracks that wrap around the snow-white moon. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Oct. 14, 2015 at a distance of approximately 6,000 miles (10,000 kilometers) from Enceladus. Image scale is 197 feet (60 meters) per pixel…. Continue…Cassini’s final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount of heat coming from the moon’s interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).
An online toolkit for all three final Enceladus flybys is available at:
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 California Institute of Technology in Pasadena. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado.
This view from NASA’s Cassini spacecraft shows battered terrain around the north pole of Saturn’s icy moon Enceladus. Craters crowd and overlap each other, each one recording an impact in the moon’s distant past. The moon’s north pole lies approximately at the top of this view from Cassini’s wide-angle camera. A companion view from the narrow-angle camera (PIA19660) shows the pole at a resolution about ten times higher… Continue…For more information about Cassini, visit:
In this episode we ask if the smallest and/or cubesat market is in a bubble that may pop?
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* Long March 2D launch of earth imaging satellites * Atlas V launches NROL-55 * Proton rocket launch with Turksat 4B * Long March 3B launch with communications satellite * United Launch Alliance selects launch pads for new Vulcan rocket * Venture Class Launch Services Contract * Virgin Galactic NewtonThree hot fire test * SpaceX to Fly Orbcomm, not SES, on First Test of Upgraded Booster
The first color images of Pluto’s atmospheric hazes, returned by NASA’s New Horizons spacecraft last week, reveal that the hazes are blue.
Pluto’s Blue Sky: Pluto’s haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn’s moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface. This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible. (Credit: NASA/JHUAPL/SwRI)“Who would have expected a blue sky in the Kuiper Belt? It’s gorgeous,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI), Boulder, Colorado.
The haze particles themselves are likely gray or red, but the way they scatter blue light has gotten the attention of the New Horizons science team. “That striking blue tint tells us about the size and composition of the haze particles,” said science team researcher Carly Howett, also of SwRI. “A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins.”
Water Ice on Pluto: Regions with exposed water ice are highlighted in blue in this composite image from New Horizons’ Ralph instrument, combining visible imagery from the Multispectral Visible Imaging Camera (MVIC) with infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA). The strongest signatures of water ice occur along Virgil Fossa, just west of Elliot crater on the left side of the inset image, and also in Viking Terra near the top of the frame. A major outcrop also occurs in Baré Montes towards the right of the image, along with numerous much smaller outcrops, mostly associated with impact craters and valleys between mountains. The scene is approximately 280 miles (450 kilometers) across. Note that all surface feature names are informal. (Credit: NASA/JHUAPL/SwRI)Scientists believe the tholin particles form high in the atmosphere, where ultraviolet sunlight breaks apart and ionizes nitrogen and methane molecules and allows them to react with each other to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules, a process first found to occur in the upper atmosphere of Saturn’s moon Titan. The more complex molecules continue to combine and grow until they become small particles; volatile gases condense and coat their surfaces with ice frost before they have time to fall through the atmosphere to the surface, where they add to Pluto’s red coloring.
In a second major finding, New Horizons has detected numerous small, exposed regions of water ice on Pluto. The discovery was made from data collected by the Ralph spectral composition mapper on New Horizons.
“Large expanses of Pluto don’t show exposed water ice,” said science team member Jason Cook, of SwRI, “because it’s apparently masked by other, more volatile ices across most of the planet. Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into.”
A curious aspect of the detection is that the areas showing the most obvious water ice spectral signatures correspond to areas that are bright red in recently released color images. “I’m surprised that this water ice is so red,” says Silvia Protopapa, a science team member from the University of Maryland, College Park. “We don’t yet understand the relationship between water ice and the reddish tholin colorants on Pluto’s surface.”
The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.
New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. APL designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.
Pluto and its largest moon Charon dance around each other, making circles around their common center of mass, which lies in an empty space between them. Around the dancing couple are four small moons. In order of increasing distance, their names are Styx (just beyond Charon), then Nix, Kerberos and Hydra. These tiny moons also orbit around the system’s center of mass. The orbits line up like a miniature solar system, except with a binary system at the center, similar to the planetary system around the star Kepler 47. All four of the small moons are less than about 30 miles (50 kilometers) in their longest dimension. Each has a lumpy shape because, unlike Pluto and Charon, they aren’t big enough for gravity to squish them into a ball.
Nix and Hydra were discovered in 2005, shortly before New Horizons launched in 2006, and their initials were a subtle nod to the New Horizons mission that started the search for them, just as the P and L in Pluto are a subtle nod to astronomer Percival Lowell, who began the search for Pluto.
The orbits of Pluto and its moons Charon, Styx, Nix, Kerberos and Hydra are illustrated around their common center of mass. Credit: SwRI/S. PorterPluto’s moon Nix is shown in high-resolution black-and-white and lower resolution color. Credit: NASA/JHUAPL/SwRIPluto’s moon Hydra as seen from NASA’s New Horizons spacecraft, July 14, 2015. Credit: NASA/JHUAPL/SwRI
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