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High-Contrast Infrared Scan Of Saturn And Its Rings

October 18, 2013 Leave a comment

This high-contrast, colorized mosaic from NASA’s Cassini mission shows an infrared view of the Saturn system, backlit by the sun, from July 19, 2013. Exaggerating the contrast of the data brings out subtleties not initially visible. For example, structures in Saturn’s wispy E ring — made from the icy breath of the moon Enceladus — reveal themselves in this exaggerated view.

The image, made from data obtained by Cassini’s visual and infrared mapping spectrometer, covers a swath of Saturn and its rings about 340,000 miles (540,000 kilometers) across that includes the planet and its rings out to the E ring, Saturn’s second most distant ring. The mosaic covers an area about 5,000 miles (8,000 kilometers) from top to bottom.

When Saturn is blocking the direct light of the sun, scientists can get a better look at the fainter rings. When small particles are lit from behind, they show up like fog in the headlights of an oncoming vehicle. Conversely, a ring that is easily seen from Earth because it is densely packed with chunks of bright water ice looks dark in these images because it is so thick that it blocks almost all of the sunlight shining behind it.

Link To Full Story

Massive Storm Pulls Water And Ammonia Ices From Saturn’s Depths

September 3, 2013 1 comment

Once every 30 years or so, or roughly one Saturnian year, a monster storm rips across the northern hemisphere of the ringed planet.

In 2010, the most recent and only the sixth giant storm on Saturn observed by humans began stirring. It quickly grew to superstorm proportions, reaching 15,000 kilometers (more than 9,300 miles) in width and visible to amateur astronomers on Earth as a great white spot dancing across the surface of the planet.

Now, thanks to near-infrared spectral measurements taken by NASA’s Cassini orbiter and analysis of near-infrared color signatures by researchers at UW-Madison, Saturn’s superstorm is helping scientists flesh out a picture of the composition of the planet’s atmosphere at depths typically obscured by a thick high-altitude haze.

Full Story: http://www.news.wisc.edu/22083

New Cassini Data From Titan indicate A Rigid, Weathered Ice Shell

August 28, 2013 Leave a comment

An analysis of gravity and topography data from Saturn’s largest moon, Titan, has revealed unexpected features of the moon’s outer ice shell. The best explanation for the findings, the authors said, is that Titan’s ice shell is rigid and that relatively small topographic features on the surface are associated with large roots extending into the underlying ocean. The study is published in the August 29 issue of the journal Nature.

Led by planetary scientists Douglas Hemingway and Francis Nimmo at the University of California, Santa Cruz, the study used new data from NASA’s Cassini spacecraft. The researchers were surprised to find a negative correlation between the gravity and topography signals on Titan.

“Normally, if you fly over a mountain, you expect to see an increase in gravity due to the extra mass of the mountain. On Titan, when you fly over a mountain the gravity gets lower. That’s a very odd observation,” said Nimmo, a professor of Earth and planetary sciences at UC Santa Cruz.

Full Story: http://news.ucsc.edu/2013/08/titan-ice-shell.html

NASA Interplanetary Probes To Take Pictures Of Earth


Two NASA spacecraft, one studying the Saturn system, the other observing Mercury, are maneuvering into place to take pictures of Earth on July 19 and 20.

The image taken from the Saturn system by NASA’s Cassini spacecraft will occur between 2:27 and 2:42 PDT (5:27 and 5:42 p.m. EDT, or 21:27 and 21:47 UTC) Friday, July 19. Cassini will be nearly 900 million miles (nearly 1.5 billion kilometers) away from Earth. NASA is encouraging the public to look and wave in the direction of Saturn at the time of the portrait and share their pictures via the Internet.

The Cassini Earth portrait is part of a more extensive mosaic — or multi-image picture — of the Saturn system as it is backlit by the sun. The viewing geometry highlights the tiniest of ring particles and will allow scientists to see patterns within Saturn’s dusty rings. Processing of the Earth images is expected to take a few days, and processing of the full Saturn system mosaic will likely take several weeks.

Full Story and Links: http://www.jpl.nasa.gov/news/news.php?release=2013-225

Revealed The Mystery Of The Gigantic Storm On Saturn


We now understand the nature of the giant storms on Saturn. Through the analysis of images sent from the Cassini space probe belonging to the North American and European space agencies (NASA and ESA respectively), as well as the computer models of the storms and the examination of the clouds therein, the Planetary Sciences Group of the University of the Basque Country has managed to explain the behaviour of these storms for the very first time. The article explaining the discovery, the lead author being Enrique García Melendo, researcher at the Fundació Observatori Esteve Duran – Institut de Ciències de l’Espai, of Catalonia, was published in Nature Geosciences.

Approximately once every Saturnian year – equivalent to 30 Earth years – an enormous storm is produced on the ringed planet and which affects the aspect of its atmosphere on a global scale. These gigantic storms are known as Great White Spots, due to the appearance they have on the atmosphere of the planet. The first observation of one of these was made in 1876; the Great White Spot of 2010 was the sixth one to be observed. On this occasion the Cassini space vehicle was able to obtain very high resolution images of this great meteorological structure.

Full Story: http://www.ehu.es/p200-hmencont/en/contenidos/noticia/20130623_tormenta_saturno/en_info/tormenta_saturno.html

Cassini Finds Hints Of Activity At Saturn Moon Dione


Image credit: NASA/JPL/Space Science Institute

Image credit: NASA/JPL/Space Science Institute

From a distance, most of the Saturnian moon Dione resembles a bland cueball. Thanks to close-up images of a 500-mile-long (800-kilometer-long) mountain on the moon from NASA’s Cassini spacecraft, scientists have found more evidence for the idea that Dione was likely active in the past. It could still be active now.

“A picture is emerging that suggests Dione could be a fossil of the wondrous activity Cassini discovered spraying from Saturn’s geyser moon Enceladus or perhaps a weaker copycat Enceladus,” said Bonnie Buratti of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who leads the Cassini science team that studies icy satellites. “There may turn out to be many more active worlds with water out there than we previously thought.”

Other bodies in the solar system thought to have a subsurface ocean – including Saturn’s moons Enceladus and Titan and Jupiter’s moon Europa – are among the most geologically active worlds in our solar system. They have been intriguing targets for geologists and scientists looking for the building blocks of life elsewhere in the solar system. The presence of a subsurface ocean at Dione would boost the astrobiological potential of this once-boring iceball.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-178

Forecast For Titan: Wild Weather Could Be Ahead


Ligeia Mare, the second largest known body of liquid on Saturn's moon Titan. Image credit: NASA/JPL-Caltech/ASI/Cornell

Ligeia Mare, the second largest known body of liquid on Saturn’s moon Titan. Image credit: NASA/JPL-Caltech/ASI/Cornell

Saturn’s moon Titan might be in for some wild weather as it heads into its spring and summer, if two new models are correct. Scientists think that as the seasons change in Titan’s northern hemisphere, waves could ripple across the moon’s hydrocarbon seas, and hurricanes could begin to swirl over these areas, too. The model predicting waves tries to explain data from the moon obtained so far by NASA’s Cassini spacecraft. Both models help mission team members plan when and where to look for unusual atmospheric disturbances as Titan summer approaches.

“If you think being a weather forecaster on Earth is difficult, it can be even more challenging at Titan,” said Scott Edgington, Cassini’s deputy project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We know there are weather processes similar to Earth’s at work on this strange world, but differences arise due to the presence of unfamiliar liquids like methane. We can’t wait for Cassini to tell us whether our forecasts are right as it continues its tour through Titan spring into the start of northern summer.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-170&cid=release_2013-170