Saturn

New Organic Compounds Found in Enceladus Ice Grains

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Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
gretchen.p.mccartney@jpl.nasa.gov

Alana Johnson
NASA Headquarters, Washington
alana.r.johnson@nasa.gov

PIA09761_hires
In this image captured by NASA’s Cassini spacecraft in 2007, the plumes of Enceladus are clearly visible. The moon is nearly in front of the Sun from Cassini’s viewpoint.Credit: NASA/JPL/Space Science Institute

New kinds of organic compounds, the ingredients of amino acids, have been detected in the plumes bursting from Saturn’s moon Enceladus. The findings are the result of the ongoing deep dive into data from NASA’s Cassini mission.

Powerful hydrothermal vents eject material from Enceladus’ core, which mixes with water from the moon’s massive subsurface ocean before it is released into space as water vapor and ice grains. The newly discovered molecules, condensed onto the ice grains, were determined to be nitrogen- and oxygen-bearing compounds.

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Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
gretchen.p.mccartney@jpl.nasa.gov

Alana Johnson
NASA Headquarters, Washington
alana.r.johnson@nasa.gov

PIA09761_hires
In this image captured by NASA’s Cassini spacecraft in 2007, the plumes of Enceladus are clearly visible. The moon is nearly in front of the Sun from Cassini’s viewpoint.Credit: NASA/JPL/Space Science Institute

New kinds of organic compounds, the ingredients of amino acids, have been detected in the plumes bursting from Saturn’s moon Enceladus. The findings are the result of the ongoing deep dive into data from NASA’s Cassini mission.

Powerful hydrothermal vents eject material from Enceladus’ core, which mixes with water from the moon’s massive subsurface ocean before it is released into space as water vapor and ice grains. The newly discovered molecules, condensed onto the ice grains, were determined to be nitrogen- and oxygen-bearing compounds.

Read the rest of this entry »

NASA’s Cassini Data Show Saturn’s Rings Relatively New

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Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.

JoAnna Wendel
NASA Headquarters, Washington DC


An artist’s concept of the Cassini orbiter crossing Saturn’s ring plane. New measurements of the rings’ mass give scientists the best answer yet to the question of their age. Credit: NASA/JPL-Caltech

 

The rings of Saturn may be iconic, but there was a time when the majestic gas giant existed without its distinctive halo. In fact, the rings may have formed much later than the planet itself, according to a new analysis of gravity science data from NASA’s Cassini spacecraft. 

The findings indicate that Saturn’s rings formed between 10 million and 100 million years ago. From our planet’s perspective, that means Saturn’s rings may have formed during the age of dinosaurs. 

The conclusions of the research – gleaned from measurements collected during the final, ultra-close orbits Cassini performed in 2017 as the spacecraft neared the end of its mission – are the best answer yet to a longstanding question in solar system science. The findings were published online Jan. 17 in Science.

 

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Scientists Finally Know What Time It Is on Saturn

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Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif. 

JoAnna Wendel 
NASA Headquarters, Washington DC

 

A view from NASA’s Cassini spacecraft shows Saturn’s northern hemisphere in 2016 as that part of the planet nears its northern hemisphere summer solstice. A year on Saturn is 29 Earth years; days only last 10:33:38, according to a new analysis of Cassini data. Credit: NASA/JPL-Caltech/Space Science Institute

 

Using new data from NASA’s Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the length of a day on Saturn. It’s 10 hours, 33 minutes and 38 seconds. 

The figure has eluded planetary scientists for decades, because the gas giant has no solid surface with landmarks to track as it rotates, and it has an unusual magnetic field that hides the planet’s rotation rate.

The answer, it turned out, was hidden in the rings. 

 

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NASA Scientists Find ‘Impossible’ Cloud on Titan — Again

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The hazy globe of Titan hangs in front of Saturn and its rings in this natural color view from NASA’s Cassini spacecraft. Image credit: NASA/JPL-Caltech/Space Science Institute

 

The puzzling appearance of an ice cloud seemingly out of thin air has prompted NASA scientists to suggest that a different process than previously thought — possibly similar to one seen over Earth’s poles — could be forming clouds on Saturn’s moon Titan.

Located in Titan’s stratosphere, the cloud is made of a compound of carbon and nitrogen known as dicyanoacetylene (C4N2), an ingredient in the chemical cocktail that colors the giant moon’s hazy, brownish-orange atmosphere. 

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Saturn Spacecraft Samples Interstellar Dust

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Of the millions of dust grains Cassini has sampled at Saturn, a few dozen appear to have come from beyond our solar system. Scientists believe these special grains have interstellar origins because they moved much faster and in different directions compared to dusty material native to Saturn. Image credit: NASA/JPL-Caltech

 

NASA’s Cassini spacecraft has detected the faint but distinct signature of dust coming from beyond our solar system. The research, led by a team of Cassini scientists primarily from Europe, is published this week in the journal Science.

Cassini has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. The spacecraft has also sampled millions of ice-rich dust grains with its cosmic dust analyzer instrument. The vast majority of the sampled grains originate from active jets that spray from the surface of Saturn’s geologically active moon Enceladus.

But among the myriad microscopic grains collected by Cassini, a special few — just 36 grains — stand out from the crowd. Scientists conclude these specks of material came from interstellar space — the space between the stars. 

Alien dust in the solar system is not unanticipated. In the 1990s, the ESA/NASA Ulysses mission made the first in-situ observations of this material, which were later confirmed by NASA’s Galileo spacecraft. The dust was traced back to the local interstellar cloud: a nearly empty bubble of gas and dust that our solar system is traveling through with a distinct direction and speed.

“From that discovery, we always hoped we would be able to detect these interstellar interlopers at Saturn with Cassini. We knew that if we looked in the right direction, we should find them,” said Nicolas Altobelli, Cassini project scientist at ESA (European Space Agency) and lead author of the study. “Indeed, on average, we have captured a few of these dust grains per year, travelling at high speed and on a specific path quite different from that of the usual icy grains we collect around Saturn.”

The tiny dust grains were speeding through the Saturn system at over 45,000 mph (72,000 kilometers per hour), fast enough to avoid being trapped inside the solar system by the gravity of the sun and its planets.

“We’re thrilled Cassini could make this detection, given that our instrument was designed primarily to measure dust from within the Saturn system, as well as all the other demands on the spacecraft,” said Marcia Burton, a Cassini fields and particles scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and a co-author of the paper.

Importantly, unlike Ulysses and Galileo, Cassini was able to analyze the composition of the dust for the first time, showing it to be made of a very specific mixture of minerals, not ice. The grains all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions. Conversely, more reactive elements like sulfur and carbon were found to be less abundant compared to their average cosmic abundance. 

“Cosmic dust is produced when stars die, but with the vast range of types of stars in the universe, we naturally expected to encounter a huge range of dust types over the long period of our study,” said Frank Postberg of the University of Heidelberg, a co-author of the paper and co-investigator of Cassini’s dust analyzer.

Stardust grains are found in some types of meteorites, which have preserved them since the birth of our solar system. They are generally old, pristine and diverse in their composition. But surprisingly, the grains detected by Cassini aren’t like that. They have apparently been made rather uniform through some repetitive processing in the interstellar medium, the researchers said.

The authors speculate on how this processing of dust might take place: Dust in a star-forming region could be destroyed and recondense multiple times as shock waves from dying stars passed through, resulting in grains like the ones Cassini observed streaming into our solar system.

“The long duration of the Cassini mission has enabled us to use it like a micrometeorite observatory, providing us privileged access to the contribution of dust from outside our solar system that could not have been obtained in any other way,” said Altobelli.

The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate in Washington. The Cosmic Dust Analyzer is supported by the German Aerospace Center (DLR); the instrument is managed by the University of Stuttgart, Germany.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

 

Saturn’s Geyser Moon Shines in Close Flyby Views

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NASA’s Cassini spacecraft has begun transmitting its latest images of Saturn’s icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles (49 kilometers) above the moon’s south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

“Cassini’s stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come,” said Linda Spilker, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Researchers will soon begin studying data from Cassini’s gas analyzer and dust detector instruments, which directly sampled the moon’s plume of gas and dust-sized icy particles during the flyby. Those analyses are likely to take several weeks, but should provide important insights about the composition of the global ocean beneath Enceladus’ surface and any hydrothermal activity occurring on the ocean floor. The potential for such activity in this small ocean world has made Enceladus a prime target for future exploration in search of habitable environments in the solar system beyond Earth.

In addition to the processed images, unprocessed, or “raw,” images appear on the Cassini mission website at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20151028

Cassini’s next and 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).

Additional information and multimedia products for Cassini’s final Enceladus flybys are available at: http://solarsystem.nasa.gov/finalflybys

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.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

NASA’s Cassini spacecraft has begun transmitting its latest images of Saturn’s icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles (49 kilometers) above the moon’s south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

“Cassini’s stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come,” said Linda Spilker, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.
Researchers will soon begin studying data from Cassini’s gas analyzer and dust detector instruments, which directly sampled the moon’s plume of gas and dust-sized icy particles during the flyby. Those analyses are likely to take several weeks, but should provide important insights about the composition of the global ocean beneath Enceladus’ surface and any hydrothermal activity occurring on the ocean floor. The potential for such activity in this small ocean world has made Enceladus a prime target for future exploration in search of habitable environments in the solar system beyond Earth.
In addition to the processed images, unprocessed, or “raw,” images appear on the Cassini mission website at: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20151028

Cassini’s next and 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).
Additional information and multimedia products for Cassini’s final Enceladus flybys are available at: http://solarsystem.nasa.gov/finalflybys

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.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

Seven Key Facts About Cassini’s Oct. 28 ‘Plume Dive’

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Cassini Flyby

 

NASA’s Cassini spacecraft will sample the ocean of Saturn’s moon Enceladus on Wednesday, Oct. 28, when it flies through the moon’s plume of icy spray.

Cassini launched in 1997 and entered orbit around Saturn in 2004. Since then, it has been studying the huge planet, its rings and its magnetic field. Here are some things to know about the mission’s upcoming close flyby of Enceladus:

  • Enceladus is an icy moon of Saturn. Early in its mission, Cassini discovered Enceladus has remarkable geologic activity, including a towering plume of ice, water vapor and organic molecules spraying from its south polar region. Cassini later determined the moon has a global ocean and likely hydrothermal activity, meaning it could have the ingredients needed to support simple life.
  • The flyby will be Cassini’s deepest-ever dive through the Enceladus plume, which is thought to come from the ocean below. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.
  • The flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.
  • Cassini scientists are hopeful the flyby will provide insights about how much hydrothermal activity — that is, chemistry involving rock and hot water — is occurring within Enceladus. This activity could have important implications for the potential habitability of the ocean for simple forms of life. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.
  • Scientists also expect to better understand the chemistry of the plume as a result of the flyby. The low altitude of the encounter is, in part, intended to afford Cassini greater sensitivity to heavier, more massive molecules, including organics, than the spacecraft has observed during previous, higher-altitude passes through the plume
  • The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions — or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below.
  • Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.

An online toolkit for all three final Enceladus flybys is available at:  http://solarsystem.nasa.gov/finalflybys

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL manages the mission for NASA’s Science Mission Directorate in Washington.

For more information about Cassini, visit:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

Cassini Prepares for Last Up-close Look at Hyperion

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This false-color view of Hyperion was obtained during Cassini’s closest flyby of Saturn’s odd, tumbling moon on Sept. 26, 2005. Image credit: NASA/JPL-Caltech/SSI

 NASA’s Cassini spacecraft will make its final close approach to Saturn’s large, irregularly shaped moon Hyperion on Sunday, May 31.

The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 21,000 miles (34,000 kilometers) at approximately 6:36 a.m. PDT (9:36 a.m. EDT). Mission controllers expect images from the encounter to arrive on Earth within 24 to 48 hours.

Mission scientists have hopes of seeing different terrain on Hyperion than the mission has previously explored in detail during the encounter, but this is not guaranteed. Hyperion (168 miles, 270 kilometers across) rotates chaotically, essentially tumbling unpredictably through space as it orbits Saturn. Because of this, it’s challenging to target a specific region of the moon’s surface, and most of Cassini’s previous close approaches have encountered more or less the same familiar side of the craggy moon.

Cassini scientists attribute Hyperion’s unusual, sponge-like appearance to the fact that it has an unusually low density for such a large object — about half that of water. Its low density makes Hyperion quite porous, with weak surface gravity. These characteristics mean impactors tend to compress the surface, rather than excavating it, and most material that is blown off the surface never returns.

Cassini’s closest-ever Hyperion flyby took place on September 26, 2005, at a distance of 314 miles (505 kilometers).

Cassini’s next notable flyby after May 31 is slated for June 16, when the spacecraft will pass 321 miles (516 kilometers) above icy Dione. That flyby will represent the mission’s penultimate close approach to that moon. In October, Cassini will make two close flybys of the active moon Enceladus, with its jets of icy spray, coming as close as 30 miles (48 kilometers) in the final pass. In late 2015, the spacecraft will again depart Saturn’s equatorial plane — where moon flybys occur most frequently — to begin a year-long setup of the mission’s daring final year. For its grand finale, Cassini will repeatedly dive through the space between Saturn and its rings.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL, a division of the California Institute of Technology, manages the mission for NASA’s Science Mission Directorate in Washington.

For more information about Cassini, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov

Saturn Moon’s Activity Could Be ‘Curtain Eruptions’

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Recent research suggests much of the eruption activity on the surface of Saturn’s moon Enceladus could be in the form of broad, curtain-like eruptions, rather than discrete jets. Image credit: NASA/JPL-Caltech/SSI/PSI
 


New research using data from NASA’s Cassini mission suggests most of the eruptions from Saturn’s moon Enceladus might be diffuse curtains rather than discrete jets. Many features that appear to be individual jets of material erupting along the length of prominent fractures in the moon’s south polar region might be phantoms created by an optical illusion, according to the new study.

The research is being published on Thursday, May 7, in the journal Nature.

“We think most of the observed activity represents curtain eruptions from the ‘tiger stripe’ fractures, rather than intermittent geysers along them,” said Joseph Spitale, lead author of the study and a participating scientist on the Cassini mission at the Planetary Science Institute in Tucson, Arizona. “Some prominent jets likely are what they appear to be, but most of the activity seen in the images can be explained without discrete jets.”

In analyzing Cassini’s images of the eruptions on Enceladus, Spitale and colleagues took particular note of the faint background glow present in most images. The brightest eruption features, which appear to be discrete jets, look to them to be superimposed intermittently upon this background structure.

The researchers modeled eruptions on Enceladus as uniform curtains along the tiger stripe fractures. They found that phantom brightness enhancements appear in places where the viewer is looking through a “fold” in the curtain. The folds exist because the fractures in Enceladus’ surface are more wavy than perfectly straight. The researchers think this optical illusion is responsible for most of what appear to be individual jets.

“The viewing direction plays an important role in where the phantom jets appear,” said Spitale. “If you rotated your perspective around Enceladus’ south pole, such jets would seem to appear and disappear.”

Phantom jets in simulated images produced by the scientists line up nicely with some of the features in real Cassini images that appear to be discrete columns of spray. The correspondence between simulation and spacecraft data suggests that much of the discrete-jet structure is an illusion, according to the researchers.

Curtain eruptions occur on Earth where molten rock, or magma, gushes out of a deep fracture. These eruptions, which often create spectacular curtains of fire, are seen in places such as Hawaii, Iceland and the Galapagos Islands.

“Our understanding of Enceladus continues to evolve, and we’ve come to expect surprises along the way,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California, who was not involved in the study. “This little ice world is becoming more exciting, not less, as we tease out new details about its subsurface ocean and astonishing geophysical activity.”

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. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about Cassini, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov

New Pages Available: NASA Apps for the Public and News Feed Links, Fact Sheets

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I have created a number of pages available that will provide you with additional information, links to news feeds, and iPad and Android Apps by NASA for a variety of missions and news.

The new pages (all pages are available when you click the three bars on the upper right hand side of the page) that have been added are:

• Mobile Apps – Connect and Collaborate With NASA Projects

A comprehensive list of both NASA’s main or featured Apps available for mobile users. Along with the featured apps, NASA also has numerous apps for everything from other facilities to current space exploration projects, live views of the Sun, ISS and Mars rover.

NASA RSS Feeds (Links)

Here this page provides the news feed (RSS) links to many of NASA’s missions, centers, science and technology, general and topical feeds. You will need to copy the links into your News or an RSS App or computer programs (Microsoft Exchange suppports RSS feeds within the mail program, for example).

NASA  Fact Sheets – NASA Centers

Each NASA center creates and updates Fact Sheets covering its mission, facilities and projects. Click on a center’s name to go its Fact Sheet index. Click on the links to veiw any fact sheet you wish to know about.

• News Feeds/Links to Other Cosmology News Sources

This page is the main page for all the RSS and XML feeds that other websites provide, such as Space.com. As we find more sites providing news stories related to Cosmology and Space Exploration, I will add it here.

As I gather more links together, I will update this message (which will stick to the top for at least seven days every time it changes) with the new links. For example, I am working on a Fact Sheet page that will provide links to every mission NASA has performed. It will at least have current missions, however, I am also going to add all missions going back to the beginning of the US space program.

George.