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Mar 24, 2011 11:29:09 GMT -6
Post by auntym on Mar 24, 2011 11:29:09 GMT -6
www.space.com/11205-saturn-strange-radio-signals-cassini.htmlWeird Saturn Radio Signals Puzzle AstronomersSPACE.com Staff Date: 23 March 2011 Time: 11:33 AM ET Saturn is sending astronomers mixed signals — radio signals, that is. NASA's Cassini spacecraft recently found that the natural radio wave signals coming from the giant planet differ in the northern and southern hemispheres, a split that can affect how scientists measure the length of a Saturn day. But the weirdness doesn't stop there, researchers say. The signal variations — which are controlled by the planet's rotation — also change dramatically over time, apparently in sync with the Saturnian seasons. "These data just go to show how weird Saturn is," said Don Gurnett of the University of Iowa, who leads Cassini's radio and plasma wave instrument team, in a statement. "We thought we understood these radio wave patterns at gas giants, since Jupiter was so straightforward. Without Cassini's long stay, scientists wouldn't have understood that the radio emissions from Saturn are so different." TO CONTINUE READING CLICK ON ABOVE LINK
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Mar 24, 2011 17:53:54 GMT -6
Post by skywalker on Mar 24, 2011 17:53:54 GMT -6
Maybe Saturn is trying to communicate with us. ;D
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Mar 3, 2012 13:25:30 GMT -6
Post by auntym on Mar 3, 2012 13:25:30 GMT -6
www.dailygalaxy.com/my_weblog/2012/03/oxygen-discovered-on-saturns-dione-joins-rhea-and-saturns-main-rings-in-having-an-oxygen-rich-exosph.htmlOxygen Discovered on Saturn's Dione --Joins Rhea and Saturn's Main Rings in Having an Oxygen-Rich ExosphereDione, one of Saturn’s 62 moons, has a weak exosphere which includes molecules of oxygen, joining Rhea and the main rings in Saturn's system in having an oxygen rich exosphere, as well as Jupiter’s moons Ganymede, Europa and Callisto - the target for ESA's proposed JUICE (JUpiter ICy moons Explorer) mission for launch in 2022 --according to new findings from the Cassini-Huygens mission. The international mission made the discovery using combined data from one of Cassini’s instruments, called CAPS (Cassini Plasma Spectrometer. The moons of Saturn ranging from tiny moonlets less than 1 kilometre across, to the enormous Titan, which is larger than the planet Mercury. Saturn has 62 moons with confirmed orbits, fifty-three of which have names, and only thirteen of which have diameters larger than 50 kilometres. “It now looks like oxygen production is a universal process wherever an icy moon is bathed in a strong trapped radiation and plasma environment," said Andrew Coates of the University College London Mullard Space Science Laboratory. “Energetic particles hit the icy surface, the hydrogen is lost and molecular oxygen remains as an exosphere. We now know that this happens at Saturn's moons as well as Jupiter's - and it may well occur in extrasolar planetary systems too.” Cassini flew by Dione on 7 April 2010. During that flyby, CAPS detected molecular oxygen ions near the moon's icy surface, due to bombardment by particles trapped in Saturn's strong magnetic field. A team of scientists, led by Robert Tokar at the Los Alamos National Laboratory in the US, used the measurements to estimate the density of the molecular oxygen ions to be in the range of 0.01 to 0.09 ions per cubic centimetre. These molecular oxygen ions are produced when neutral molecules are ionized; the measurements confirm that a neutral exosphere surrounds Dione. CONTINUE READING: www.dailygalaxy.com/my_weblog/2012/03/oxygen-discovered-on-saturns-dione-joins-rhea-and-saturns-main-rings-in-having-an-oxygen-rich-exosph.html
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Mar 3, 2012 16:45:57 GMT -6
Post by swamprat on Mar 3, 2012 16:45:57 GMT -6
More on Dione Saturn's Icy Moon Dione Has Oxygen AtmosphereSPACE.com Staff Date: 02 March 2012 This view highlights tectonic faults and craters on Saturn's moon, Dione, an icy world that has undoubtedly experienced geologic activity since its formation. It is based on images from the the Cassini spacecraft. CREDIT: NASA/JPL/Space Science Institute A NASA spacecraft circling Saturn has discovered a wispy oxygen atmosphere on the ringed planet's icy moon Dione, but you wouldn't want to live there. For one thing, you wouldn't be able to breathe — Dione's atmosphere is 5 trillion times less dense than the air at Earth's surface, scientists say. Dione's atmosphere was detected by NASA's Cassini spacecraft, which spotted an ultra-thin layer of oxygen ions so sparse that it is equivalent to conditions 300 miles (480 kilometers) above Earth. On Dione, there is just one oxygen ion one for every 0.67 cubic inches (or one ion for every 11 cubic centimeters) of space, but it's still enough to qualify as an atmosphere, Cassini mission scientists announced Friday (March 2). "We now know that Dione, in addition to Saturn's rings and the moon Rhea, is a source of oxygen molecules," Cassini team member Robert Tokar of the Los Alamos National Laboratory in New Mexico, who led the new study, said in a statement. "This shows that molecular oxygen is actually common in the Saturn system and reinforces that it can come from a process that doesn't involve life." Dione is one of Saturn's smaller moons and is about 698 miles (1,123 km) wide. It orbits Saturn once every 2.7 days at a distance of about 234,000 miles (377,400 km) — roughly the same as that between Earth and its moon, according to a NASA description. www.space.com/14775-saturn-moon-dione-oxygen-atmosphere.html
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Mar 25, 2012 12:04:09 GMT -6
Post by auntym on Mar 25, 2012 12:04:09 GMT -6
www.stumbleupon.com/su/1uKQqO/www.dailygalaxy.com/my_weblog/2012/03/saturns-titan-earth-only-worlds-in-solar-system-that-have-rainfall.htmlMarch 23, 2012 Saturn's Titan & Earth --"Only Worlds in Solar System that Have Rainfall"[/color] In image above, NASAs Cassini spacecraft chronicled the change of seasons as it captured clouds concentrated near the equator of Saturns largest moon, Titan, on Oct. 18, 2010. Dr. Ralph Lorenz of Johns Hopkins Applied Physics Laboratory, gave a talk this week at the Lunar and Planetary Science Conference (LPSC) in Texas summarizing what NASA has learned about rainfall on Titan, one of Saturn’s moons. In his talk, Lorenz proposed sending a probe to its surface to study the rainfall in more detail. Titan and Earth are the only “worlds” in our solar system that have rainfall, except that on Titan, it rains methane, not water. Lorenz’s probe mission is one of three currently being considered by NASA, with the winner to be announced this April. Lorenz pointed out that the Cassini mission recoreded what is believed to have been rainfall on Titan has been observed in the past; once in 2004 and then again in 2007, which has led to the formation of rivers, lakes and streams despite an annual surface temperature of just -179°C. Titan receives far less rain than Earth, and has far less clouds. On Earth, we typically get 50-65% cloud cover at any given time, whereas on Titan, it’s more like 0.2-0.6%, which results in centuries passing between rain showers, which as expected dump a lot of rain when they do occur. When observing Titan's poles, the rainfall appears to occur far more often. In fact, Lorenz points out, if a probe were to sit on the surface near the northern pole, it would have a fifty-fifty chance of being rained on if it sat there for 2500 hours (96 Earth days), which he is suggesting would be the duration of his proposed Titan Mare Explorer (TiME), which would land in Ligeia Mare, one of Titan’s lakes sometime in 2023. In the earlier rain showers recorded by the Cassini probe, dark patches appeared on Titan’s surface, in sync with cloud cover. Researchers observed that the dark patches slowly disappeared, consistent with evaporation. These conclusions were supported by Dr Elizabeth Turtle, with Planetary Image Research Lab. at the University of Arizona, who spoke at the conference in support of the Lorenz mission, saying that her studies of the more recent rainfall, showed that the texture of the surface had changed significantly with dark patches on the surface covering about 500,000 sq km which could be clearly seen after the passing of the cloud cover. CONTINUE READING: www.stumbleupon.com/su/1uKQqO/www.dailygalaxy.com/my_weblog/2012/03/saturns-titan-earth-only-worlds-in-solar-system-that-have-rainfall.html
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Oct 17, 2013 12:25:40 GMT -6
Post by auntym on Oct 17, 2013 12:25:40 GMT -6
www.davidreneke.com/raining-diamonds-on-saturn-and-jupiter/ Diamond Drizzle Forecast for Saturn and Jupiter.Forget diamonds in the sky — it may actually be raining diamonds on Saturn and Jupiter, according to two planetary scientists. It seems the solar system is mineral rich indeed. Researchers have long wondered whether the high pressures inside the giant planets could turn carbon into diamond, and even though some researchers dispute their claim, Mona Delitsky of California Specialty Engineering in Flintridge, and Kevin Baines of the University of Wisconsin-Madison, now say it is possible. They are laying out their argument this week at a meeting of the American Astronomical Society’s Division for Planetary Sciences in Denver, Colorado. In their scenario, lightning zaps molecules of methane in the upper atmospheres of Saturn and Jupiter, liberating carbon atoms. These atoms then stick onto each other, forming larger particles of carbon soot, which the Cassini spacecraft may have spotted in dark storm clouds on Saturn. As the soot particles slowly float down through ever-denser layers of gaseous and liquid hydrogen towards the planets’ rocky cores, they experience ever greater pressures and temperatures. The soot is compressed into graphite, and then into solid diamonds before reaching a temperature of about 8,000 °C, when the diamond melts, forming liquid diamond raindrops, they say. CONTINUE READING: www.davidreneke.com/raining-diamonds-on-saturn-and-jupiter/
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May 13, 2014 11:25:41 GMT -6
Post by auntym on May 13, 2014 11:25:41 GMT -6
www.universetoday.com/111836/saturn-disappears-behind-the-full-flower-moon-may-14-watch-it-live/#ixzz31Wzhdddl Saturn Disappears Behind the Full Flower Moon May 14 – Watch it Liveby Bob King on May 12, 2014 Simulation of the moon closing in on Saturn just prior to occultation. Click to go to the Virtual Telescope website where you’ll be able to watch the May 14 event live. Credit: Gianluca Masi using SkyX software Funny thing. Skywatchers are often just as excited to watch a celestial object disappear as we are to see it make an appearance. Early Wednesday morning (May 14) the Full Flower Moon will slip in front of Saturn, covering it from view for about an hour for observers in Australia and New Zealand. If you don’t live where the dingoes roam, no worries. You can watch it online.And no matter where you are on the planet, the big moon will accompany the ringed planet across the sky this Tues. night-Weds. morning. Occultations of stars happen swiftly. The moon’s limb meets the pinpoint star and bam! it’s gone in a flash. But Saturn is an extended object and the moon needs time to cover one end of the rings to the other. Planetary occultations afford the opportunity to remove yourself from planet Earth and watch a planet ‘set’ and ‘rise’ over the alien lunar landscape. Like seeing a Chesley Bonestell painting in the flesh. www.outer-space-art-gallery.com/chesley-bonestell.htmlSaturn and the moon tomorrow night just before midnight as viewed from the Midwestern U.S. View faces south-southeast. Stellarium Saturn and the moon Tuesday night (May 13) just before midnight as viewed from the U.S. Stellarium As the moon approaches Saturn, the planet first touches the lunar limb and then appears to ‘set’ as it’s covered by degrees. About an hour later, the planet ‘rises’ from the opposite limb. Planetary occultations are infrequent and always worth the effort to see. Saturn and the moon Tuesday night (May 13) just before midnight as viewed from the U.S. Stellarium Seen from the northern hemisphere and equatorial regions, the nearly full moon will appear several degrees to the right or west of Saturn tomorrow night (May 13). As the night deepens and the moon rolls westward, the two grow closer and closer. They’ll be only a degree apart (two full moon diameters) during Wednesday morning twilight seen from the West Coast. Northern hemisphere viewers will notice that the moon slides to the south of the planet overnight Read more: www.universetoday.com/111836/saturn-disappears-behind-the-full-flower-moon-may-14-watch-it-live/#ixzz31cN0i49V
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May 15, 2014 13:09:09 GMT -6
Post by auntym on May 15, 2014 13:09:09 GMT -6
www.dailygalaxy.com/Cassini: Coming Attractions at Saturn Published on Mar 14, 2014 What incredible things will the Cassini spacecraft at Saturn see and do over the next few years? Here's a preview. www.dailygalaxy.com/
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Jun 18, 2014 15:47:20 GMT -6
Post by swamprat on Jun 18, 2014 15:47:20 GMT -6
NASA Probe Flying by Huge Saturn Moon Titan Today By Mike Wall, Senior Writer | June 18, 2014
NASA's Cassini spacecraft is scheduled to fly by Saturn's moon Titan today (June 18) to learn more about the huge satellite's thick atmosphere and frigid, sea-studded surface.
During today's encounter — the 103rd Titan flyby for Cassini over its long operational life — the probe will skim just 2,274 miles (3,660 kilometers) above the moon at a speed of 13,000 mph (20,920 km/h), NASA officials said.
Cassini will bounce radio signals off the big Saturn moon toward Earth, where they'll be picked up by the antennas of NASA's Deep Space Network. Scientists will then pore over the signals for clues about Titan's surface, which harbors several large liquid-hydrocarbon seas.
Cassini did something similar during its previous Titan flyby on May 17, bouncing signals off the moon's two largest seas, which are called Ligeia Mare and Kraken Mare.
"We held our breath as Cassini turned to beam its radio signals at the lakes," Cassini radio science team member Essam Marouf, of San Jose State University in California, said in statement. "We knew we were getting good quality data when we saw clear echoes from Titan's surface. It was thrilling."
Mission team members will also send radio signals from Earth to Cassini through Titan's atmosphere today, and the probe will respond with an identical signal.
The experiment — which should reveal how temperature varies by altitude in the moon's nitrogen-dominated air — is tricky to execute. The signal has to be varied so that it remains constant when Cassini receives it despite the influence of Titan's atmosphere, researchers said.
Cassini scientists have confidence they can pull it off, however, since they did so successfully during the May 17 Titan flyby.
"This was like trying to hit a hole-in-one in golf, except that the hole is close to a billion miles away, and moving," Cassini project manager Earl Maize, of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "This was our first attempt to precisely predict and compensate for the effect of Titan's atmosphere on the uplinked radio signal from Earth, and it worked to perfection."
The $3.2 billion Cassini mission launched in 1997 and entered orbit around Saturn in 2004. The Cassini's operations have been extended through 2017, when the probe will end its life with a dramatic plunge into Saturn's atmosphere.
www.space.com/26286-nasa-cassini-spacecraft-titan-flyby.html
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Jun 13, 2015 11:56:13 GMT -6
Post by auntym on Jun 13, 2015 11:56:13 GMT -6
sen.com/news/saturn-s-largest-ring-is-bigger-than-we-thought Saturn's largest ring is bigger than we thoughtMorgan Rehnberg, Correspondent Jun 12, 2015 Sen—Sometimes the big just get bigger. Ever since its initial discovery in 2009, Saturn’s Phoebe ring has reigned supreme as the planet’s largest ring. It was already known to be more than ten times bigger than the next-largest ring. Now new research unveiled this week has revealed that Saturn’s outermost ring is nearly twice as large as previously thought. Stretching out to more than 15 million kilometers from the planet, it is now believed to be the largest in the Solar System. How did such a large structure evade our detection for so long? Unlike most other rings, this one is not predominately comprised of water. Instead, it is made of tiny chips of rocks blasted off of one of Saturn’s darkest moons by micrometeoroid impacts. The surface of its namesake moon Phoebe reflects just eight per cent of incoming light, a far cry from the shiny surfaces of most other large Saturnian moons. The ring is so distant and dark that it is actually more easily observed from Earth than by the Cassini spacecraft in orbit about Saturn. This latest work made use of NASA’s Wide-field Infrared Survey Explorer, an Earth-orbiting space telescope. Although we did not spot the Phoebe ring until 2009, hints of its existence had long been present. Orbiting four times closer to Saturn than Phoebe, the moon Iapetus sports a dramatic color dichotomy. While one half of Iapetus is as bright as many of the planet’s other moons, the other half appears as dark as Phoebe. Scientists had long speculated that material from Phoebe must be falling in onto Iapetus, a hypothesis confirmed by the discovery of the ring. CONTINUE READING: sen.com/news/saturn-s-largest-ring-is-bigger-than-we-thought
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Aug 11, 2015 11:06:37 GMT -6
Post by auntym on Aug 11, 2015 11:06:37 GMT -6
www.space.com/30197-saturn-rings-math-rule.html?cmpid=514648_20150810_50577116&adbid=630785762431111168&adbpl=tw&adbpr=15431856 Surprising Math Rules of Saturn's Rings Revealedby Sarah Lewin, Staff Writer | August 10, 2015 [Pin It] This image, created with data from the Cassini mission, shows where particles smaller than 5 centimeters are rare (purple) and common (green), and where particles smaller than 1 centimeter are common (blue). Credit: NASA As particles race around Saturn at breakneck speeds, their jostling and crashing may look random and haphazard — but a new mathematical theory brings a simple kind of order to the chaos that will help reveal more about rings across the universe. A group of physicists, mathematicians and astronomers has more rigorously explained a longstanding mystery of Saturn's rings: why the distribution of different particle sizes, ranging from inches to more than 30 feet (10 meters) across, follows a very simple ratio. Their model also suggests why very large bodies in the rings never last long. The theory not only explains the regularity of Saturn's rings, but also may reveal more about planets' and asteroids' ages and conditions based on the distribution of their rings. [Photos: Saturn's Glorious Rings Up Close] "The law follows from a 1-centimeter-sized (0.4 inches) particle to house-sized," said Nikolai Brilliantov, a mathematician at the University of Leicester in England and lead author of the new study. "This is mathematically quite beautiful, but [we had] no idea why it happens. Now, we understand that it's perfectly correct, and we know why, and can prove that there is a very universal mechanism behind these particular features." Saturn is surrounded by immense rings built of chunks of water ice, with a sprinkling of rocky material. The rings can reach a width of 185,000 miles (300,000 kilometers), and the particles can travel at thousands of miles per hour. Researchers have found that the rings' particles are loose and porous. When two particles collide, if they're moving slowly enough, they will merge into one — but if they're moving too quickly, they'll shatter. The new model shows mathematically how this simple behavior agrees with the strangely precise distribution of the particle's sizes. [Saturn Quiz: Do You Know the Ringed Planet?] Since the 1980s, researchers have noticed a strict ratio in the sizes of particles in Saturn's rings — that it roughly followed an "inverse cube law." For instance, a particle two times larger than another will be eight times less common, and a particle three times larger will be 27 times less common. The new mathematical model starts with merging and fracturing particles, and finds that the distribution would be very similar to this rule of 3 — between 2.75 and 3.5. And it would have that same drop-off with very few particles above a certain size. "Usually, astrophysicists try to solve their problems, but they are not equipped with the new [mathematical] tools," Brilliantov said. Over the course of seven years, the researchers studied the mechanical properties of ice, collisions and fragmentation to work into their model of how granules behave, verifying that the ratio can emerge out of real-world starting rules through calculations on a Moscow supercomputer. CONTINUE READING: www.space.com/30197-saturn-rings-math-rule.html?cmpid=514648_20150810_50577116&adbid=630785762431111168&adbpl=tw&adbpr=15431856
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Sept 29, 2015 12:32:51 GMT -6
Post by swamprat on Sept 29, 2015 12:32:51 GMT -6
Something Strange Is Happening Inside Saturn by Sarah Lewin, Staff Writer September 29, 2015
Unusual ripples in Saturn's rings are revealing the mysterious inner workings of the great gas giant. Planetary scientists and modelers are slowly picking apart that mystery.
Billions of particles race around Saturn's 170,000-mile-wide (273,600 kilometers) set of rings, which are mostly water ice with a smattering of rock. The rings are full of activity, including waves that ricochet outward in spiral patterns, most caused by the gravitational pull of Saturn's 62 moons. Waves caused by the moons, which orbit outside the rings' sphere, always travel outward.
But then there's a set of waves heading inward. That means there's something moving inside, too.
Most scientists' models of Saturn and other gas giants assume the planet is pretty uniform — just a large gas envelope surrounding a small, dense core that's perhaps the size of Earth. But by studying the rings' waves, researchers are finding the picture much more complicated.
"The one thing that might produce this [series of waves] is that some sort of disturbance inside Saturn itself is spinning around with a period that's less than 7 hours," Phillip Nicholson, a planetary scientist at Cornell University in New York, told Space.com. Researchers first noticed hints of that disturbance in the 1990s, and Nicholson's team used more precise measurements to fully document the ring waves' structures, which reflect the oscillations of the planet within — sort of like recurring Saturn quakes.
Right now, measuring those oscillations offers scientists the best possible chance to grasp what's going on far inside the planet, like Saturn's internal rotation or structure, which appears to be more complicated than previously thought, scientists say.
"Even dropping a probe into the atmosphere would not necessarily help a lot, because the probe will only get down to a pressure of five or 10 atmospheres before it gets cooked or squashed," Nicholson said. "We need to go much deeper to understand this."
Something strange When Nicholson put together the series of waves caused by Saturn's movement for a 2013 paper, they didn't quite add up. Instead of a regular pattern of vibrations all building on one another, he was seeing multiples of some waves and missing others.
"If Saturn were a nice big ball of liquid hydrogen and helium, liquid and gas, it really should only have one frequency associated with each of these overtones," he said. Instead, the measurements were like a violin that plays multiple discordant tones when one string is strummed. There's "something a bit wrong with your violin, if that's the case," he said.
Fuller has conducted follow-up research to try to find the possible causes of the discord. "Saturn must have a layer deep down inside of it that's stably stratified," he said. "For some reason, the fluid is very stable and doesn't move around very much ... And that part is new, because the conventional models of giant planets are just convective envelopes [where the materials move freely to exchange heat] all the way down to their core. But what I found is that those very simple models can't explain what we're seeing in the rings."
Fuller suggested that the stable layers could have a number of causes. By modeling each potential scenario and measuring the waves it would create, he and others are hoping to narrow down the possibilities. One explanation, he said, is that the helium is separating from its mix with hydrogen lower down in the planet, because of higher pressure, and condensing into helium raindrops that fall even deeper. Then, the boundary between the high-helium area below and the mostly hydrogen area above would be a stable border, Fuller said.
Another explanation might be that the ice and rock of the core are dissolving upward into the hydrogen and helium that make up most of the planet. That, too, would create smooth layers of fluid beneath the turbulent gas above.
"In the past, people have thought of these ideas, but it's been very hard to test them because we have no way of seeing what's inside of Saturn," Fuller said. "But with the seismology, for the first time, we're starting to get a glimpse of that interior structure. It's still pretty primitive, because we can only detect some of Saturn's operations, but it's enough to give us some interesting prospects, at the very least.
Read more: www.space.com/30665-unraveling-saturn-ring-mystery.html
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Oct 1, 2015 17:59:54 GMT -6
Post by skywalker on Oct 1, 2015 17:59:54 GMT -6
It's amazing the stuff we are just now learning about space and the solar system. I didn't even know there were ripples in Saturn's rings. What crazy stuff will we learn next?
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Apr 12, 2017 12:30:29 GMT -6
lois likes this
Post by swamprat on Apr 12, 2017 12:30:29 GMT -6
Saturn Spacecraft Begins Science Swan-song
NASA’s Cassini probe will go where no spacecraft has gone before — between a planet and its rings.
Alexandra Witze 12 April 2017
Scientists still debate the age and origin of Saturn’s rings, but the Cassini craft’s final months promise to tell us more about their provenance. (NASA/JPL)
After 13 years exploring Saturn and its moons, NASA’s Cassini spacecraft has just 5 months left to live. But it will go out with a scientific bang.
On 22 April, Cassini will slingshot past Titan, Saturn’s largest moon, for the last time. Four days later, the probe will hurtle into the unexplored region between the giant planet and its rings. Cassini will thread that 2,400-kilometre-wide gap 22 times before its kamikaze dive into Saturn’s atmosphere on 15 September.
This unprecedented journey promises to yield fresh discoveries for the venerable spacecraft. “It will be like a whole new mission,” says Linda Spilker, Cassini’s project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “There are fundamental new scientific measurements to make.” Those include the first direct tastes of particles in Saturn’s rings, and of its upper atmosphere; the best measurements yet of the planet’s magnetic and gravitational fields, which could answer long-standing questions such as how fast the planet rotates and how old its rings are; and the sharpest look yet at enigmatic ripples in the rings.
It all begins with the spacecraft’s final fly-by of Titan, the 127th such close encounter. Cassini will scan the moon’s methane lakes one last time, looking for waves, bubbles or other phenomena roiling the surface. Earlier fly-bys have revealed changes in the lakes over time, and the final pass is the last chance to look for seasonal shifts, says Sarah Hörst, a planetary scientist at Johns Hopkins University in Baltimore, Maryland.
Titan’s gravitational pull will fling Cassini into its ‘grand finale’ orbits, plunging between Saturn’s innermost ring and the planet’s cloud tops (see ‘Cassini: the final frontier’). The spacecraft will turn its main antenna forward, to act as a protective shield against any errant ring particles as it whizzes along at 110,000 kilometres per hour.
Since November, the probe has been climbing higher relative to Saturn’s equatorial plane, providing a new vantage point on the planet’s outer rings. The upcoming inner dives will also reveal spectacular new details, says Carolyn Porco, a planetary scientist at the University of California, Berkeley, who leads the mission’s imaging team.
High-resolution photographs will capture the mysterious propeller-shaped gaps that ripple through some of the rings, probably formed by unseen moonlets. “The rings really are changing before our eyes,” says Jeffrey Cuzzi, a planetary scientist at NASA’s Ames Research Center in Moffett Field, California.
Cassini’s remote-sensing instruments will get their closest look yet at the rings, on sides both lit and unlit by the Sun. Measurements will show how the chemical make-up of the ring particles varies from place to place — information that is crucial for researchers who are trying to tease out which compounds pollute the rings’ otherwise pure ice.
And scientists might finally unravel the rings’ biggest mystery — how old they are and how they formed. Between May and July, Cassini will make its most precise measurements of Saturn’s gravitational field; by tracking the spacecraft’s motion as it flies between the planet and the rings, mission scientists expect to improve their calculations of the mass of the rings by an order of magnitude. A relatively high mass would suggest that the rings were ancient, perhaps formed by a big moon ripped apart billions of years ago. Lighter-weight rings would suggest a more recent formation, perhaps from a visiting comet that disintegrated.
Other fundamental measurements will tackle the giant planet itself. On the grand-finale orbits, Cassini’s magnetometer will measure Saturn’s magnetic field close to the planet. There, it is roughly ten times stronger — and more complex and scientifically interesting — than in areas already probed, says Marcia Burton, a planetary scientist at JPL.
Those data should shed light on long-standing mysteries such as the depth of Saturn’s metallic hydrogen core — which powers its magnetic field — and how quickly the planet rotates. Observations by the Voyager spacecraft in the 1980s suggested that one rotation takes just under 11 hours. But the numbers are different when measured in the northern and southern hemispheres, which hints that something more complicated is going on. “It is hard to imagine how the grand-finale orbits could not lead to a huge improvement in our understanding of Saturn’s magnetic field,” Burton says.
On 15 September, with its tanks almost out of fuel, mission controllers will steer Cassini directly into Saturn. But the craft will still radio back observations of the gases that make up Saturn’s atmosphere. “Even in its final moments, Cassini will be doing groundbreaking science,” says Hörst.
www.nature.com/news/saturn-spacecraft-begins-science-swan-song-1.21813?WT.ec_id=NEWSDAILY-20170412
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May 2, 2017 10:41:11 GMT -6
Post by swamprat on May 2, 2017 10:41:11 GMT -6
Cassini finds ‘big empty’ near SaturnBy Deborah Byrd in Space May 2, 2017
It’s not totally empty, but the space between Saturn and its rings is much emptier than scientists expected. Cassini will make its 2nd dive through this gap at 3:38 p.m. EDT (19:38 UTC) today.
There’s much less dust between Saturn and its inner rings than expected, said NASA engineers, after last week’s historic dive through this gap by the Cassini spacecraft. Astronomers have been contemplating this maneuver by a spacecraft for decades, since the two Voyager spacecraft passed Saturn in the early 1980s. The fear was that a spacecraft might encounter debris that would suddenly end its mission! But Cassini – which is running out of fuel after orbiting Saturn since 2004 – not only passed through the gap successfully but also found it surprising debris-free. Cassini Project Manager Earl Maize of NASA’s Jet Propulsion Laboratory in Pasadena, California said:
The region between the rings and Saturn is ‘the big empty,’ apparently. Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected.
Cassini will make its second dive through the gap today (May 2, 2017) at 12:38 p.m. PDT (3:38 p.m. EDT, 19:38 UTC; translate UTC to your time zone)
With information from the first dive in hand, the Cassini team will now move forward with its preferred plan of science observations. NASA said:
A dustier environment in the gap might have meant the spacecraft’s saucer-shaped main antenna would be needed as a shield during most future dives through the ring plane. This would have forced changes to how and when Cassini’s instruments would be able to make observations. Fortunately, it appears that the “plan B” option is no longer needed. (There are 21 dives remaining. Four of them pass through the innermost fringes of Saturn’s rings, necessitating that the antenna be used as a shield on those orbits.)
Based on images from Cassini, models of the ring particle environment in the approximately 1,200-mile-wide (2,000-kilometer-wide) region between Saturn and its rings suggested the area would not have large particles that would pose a danger to the spacecraft.
But because no spacecraft had ever passed through the region before, Cassini engineers oriented the spacecraft so that its 13-foot-wide (4-meter-wide) antenna pointed in the direction of oncoming ring particles, shielding its delicate instruments as a protective measure during its April 26 dive.
The video below represents data collected by Cassini’s Radio and Plasma Wave Science instrument, as it crossed through the gap between Saturn and its rings on April 26. The instrument is able to record ring particles striking the spacecraft in its data. In the data from this dive, there is virtually no detectable peak in pops and cracks that represent ring particles striking the spacecraft. The lack of discernible pops and cracks indicates the region is largely free of small particles. William Kurth, RPWS team lead at the University of Iowa, Iowa City said:
It was a bit disorienting — we weren’t hearing what we expected to hear. I’ve listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear.
The team’s analysis suggests Cassini only encountered a few particles as it crossed the gap — none larger than those in smoke (about 1 micron across).
Today’s ring crossing will occur in a region very close to where Cassini passed on last week’s dive. Prior to today’s crossing, Cassini’s cameras have been looking closely at the rings; in addition, the spacecraft was rotated (or “rolled”) faster than engineers have ever allowed it to before, in order to calibrate the magnetometer.
As with the first finale dive, Cassini will be out of contact during closest approach to Saturn, and is scheduled to transmit data from this dive on May 3.
Bottom line: During its April 26, 2017 dive between Saturn and its rings – its first of 22 dives in its Grand Finale this year – the Cassini spacecraft found a relatively dust-free region. Scientists are calling it The Big Empty.
earthsky.org/space/cassini-saturn-big-empty-2nd-dive-grand-finale?utm_source=EarthSky+News&utm_campaign=181009ec56-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-181009ec56-394368745&mc_cid=181009ec56&mc_eid=9b2daed519
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May 28, 2017 7:27:02 GMT -6
Post by swamprat on May 28, 2017 7:27:02 GMT -6
It must be fun to sit around and wait....... Cassini Takes Most Dangerous Saturn Ring Dive Yet By Sarah Lewin, Staff Writer May 28, 2017
The Cassini spacecraft completes its sixth dive between Saturn and its rings today (May 28), and this is the most dangerous dive yet. Instead of passing safely between the planet and its rings, the spacecraft is plunging straight through the inner edge of Saturn's D ring.
The spacecraft, which is a collaboration between NASA, the European Space Agency and the Italian Space Agency, will turn its broad, high-gain antenna dish to rest in front of it as a shield during the crossing, for the first time since its very first ring dive, which occurred in April, NASA officials said. (For that dive, researchers didn't know whether the area between the rings and Saturn would be clear of debris.)
This dive is the first of four paths through the planet's faint innermost ring, and it's the deepest Cassini will go into the dusty loop, according to NASA's Grand Finale Orbit Guide. The spacecraft will make the crossing at 10:22 a.m. EDT (1422 GMT), but researchers don't expect to hear back from it until 11:29 p.m. EDT (0329 on May 29 GMT) once it is able to turn and reestablish contact with Earth.
Researchers have identified the 6-minute period when Cassini is most likely to collide with ring particles. During this time, the spacecraft's Radio and Plasma Wave Science instrument will be poised to detect the plasma clouds released when particles hit the antenna dish. The instrument sticks out past the dish, letting it take stock of particles while the rest of the craft is protected, the guide said.
During this orbit around Saturn, Cassini has been taking photos of the edge of the planet's A and F rings, as well as the space between, to investigate the rings' structure and how their particles interact. It also used the Radar instrument to scan all the way from the A ring's outer edge through the C ring, in the first of a three-part radio-wave experiment.
Cassini's next dive will also take it through the edge of the D ring, although not as far, and it will have two more opportunities after that to get firsthand experience of the planet's ephemeral innermost ring.
After Cassini completes all 22 ring dives, it will begin the final phase of its Grand Finale mission: plummeting into Saturn's atmosphere on Sept. 15 in its most dangerous (and fatal) dive of all. The spacecraft will send data back until it loses contact and burns up; the maneuver will protect Saturn's moons from any further contamination by Earth microbes and collect invaluable details about the planet's atmosphere in its last moments.
But in the meantime, Cassini has lots of science to do.
www.space.com/37010-cassini-most-dangerous-ring-dive-yet.html
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Sept 5, 2017 9:54:12 GMT -6
Post by swamprat on Sept 5, 2017 9:54:12 GMT -6
Cassini: Milestones before the final plungeBy Eleanor Imster in Space August 31, 2017 The 20-year-old Cassini mission will end September 15 with a dramatic plunge into planet Saturn. Here are the milestones for Cassini’s final days.
The Cassini spacecraft’s fateful plunge into planet Saturn on September 15, 2017 is a foregone conclusion, said NASA, as an April 22 gravitational kick from Saturn’s moon Titan placed the two-and-a-half ton vehicle on its path for impending destruction. Yet several mission milestones have to occur over the coming two-plus weeks to prepare the vehicle for one last burst of trailblazing science.
Linda Spilker, Cassini project scientist from NASA’s Jet Propulsion Laboratory in Pasadena, California. She said in a statement:
"The Cassini mission has been packed full of scientific firsts, and our unique planetary revelations will continue to the very end of the mission as Cassini becomes Saturn’s first planetary probe, sampling Saturn’s atmosphere up until the last second. We’ll be sending data in near real time as we rush headlong into the atmosphere – it’s truly a first-of-its-kind event at Saturn."
The spacecraft is expected to lose radio contact with Earth within about one to two minutes after beginning its descent into Saturn’s upper atmosphere. But on the way down, before contact is lost, eight of Cassini’s 12 science instruments will be operating. On the day before the plunge, Cassini will make detailed, high-resolution observations of Saturn’s auroras, temperature, and the vortices at the planet’s poles. Cassini’s imaging camera will be off during this final descent, having taken a last look at the Saturn system the previous day (September 14).
In its final week, Cassini will pass several milestones en route to its Saturn plunge. (Times below are predicted and may change slightly; see go.nasa.gov/2wbaCBT for updated times.)
September 9 Cassini will make the last of 22 passes between Saturn itself and its rings – closest approach is 1,044 miles (1,680 kilometers) above the clouds tops.
September 11 Cassini will make a distant flyby of Saturn’s largest moon, Titan. Even though the spacecraft will be at 73,974 miles (119,049 kilometers) away, the gravitational influence of the moon will slow down the spacecraft slightly as it speeds past. A few days later, instead of passing through the outermost fringes of Saturn’s atmosphere, Cassini will dive in too deep to survive the friction and heating.
September 14 Cassini’s imaging cameras take their last look around the Saturn system, sending back pictures of moons Titan and Enceladus, the hexagon-shaped jet stream around the planet’s north pole, and features in the rings.
September 14 (5:45 p.m. EDT / 21:45 UTC) Cassini turns its antenna to point at Earth, begins a communications link that will continue until end of mission, and sends back its final images and other data collected along the way.
September 15 (4:37 a.m. EDT / 8:37 UTC) The “final plunge” begins. The spacecraft starts a 5-minute roll to position its instruments for optimal sampling of the atmosphere, transmitting data in near real time from now to end of mission.
September 15 (7:53 a.m. EDT / 11:53 UTC) Cassini enters Saturn’s atmosphere. Its thrusters fire at 10 percent of their capacity to maintain directional stability, enabling the spacecraft’s high-gain antenna to remain pointed at Earth and allowing continued transmission of data.
September 15 (7:54 a.m. EDT / 11:54 UTC) Cassini’s thrusters are at 100 percent of capacity. Atmospheric forces overwhelm the thrusters’ capacity to maintain control of the spacecraft’s orientation, and the high-gain antenna loses its lock on Earth. At this moment, expected to occur about 940 miles (1,510 kilometers) above Saturn’s cloud tops, communication from the spacecraft will cease, and Cassini’s mission of exploration will have concluded. The spacecraft will break up like a meteor moments later.
Find out more about the Cassini mission here: www.nasa.gov/mission_pages/cassini/main/index.html
NASA said:
"Since its launch in 1997, the findings of the Cassini mission have revolutionized our understanding of Saturn, its complex rings, the amazing assortment of moons and the planet’s dynamic magnetic environment. The most distant planetary orbiter ever launched, Cassini started making astonishing discoveries immediately upon arrival and continues today. Icy jets shoot from the tiny moon Enceladus, providing samples of an underground ocean with evidence of hydrothermal activity. Titan’s hydrocarbon lakes and seas are dominated by liquid ethane and methane, and complex pre-biotic chemicals form in the atmosphere and rain to the surface. Three-dimensional structures tower above Saturn’s rings, and a giant Saturn storm circled the entire planet for most of a year. Cassini’s findings at Saturn have also buttressed scientists’ understanding of processes involved in the formation of planets."
Bottom line: The NASA Cassini spacecraft’s mission-ending dive into the atmosphere of Saturn is September 15, 2017. Mission milestones 2+ weeks ahead.
earthsky.org/space/cassinis-saturn-plunge-september15-mission-milestone?mc_cid=50b5fa50f7&mc_eid=9b2daed519
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Sept 14, 2017 9:25:25 GMT -6
Post by swamprat on Sept 14, 2017 9:25:25 GMT -6
Cassini in final approach to SaturnBy EarthSky in Space September 13, 2017
Click the links to see the last raw images gathered by Cassini prior to Friday’s plunge into Saturn, and to follow the mission’s fiery end online.
NASA’s Cassini spacecraft is on final approach to Saturn, following confirmation by mission navigators that it is on course to dive into the planet’s atmosphere on Friday, September 15, 2017.
Cassini is ending its 13-year tour of the Saturn system with an intentional plunge into the planet to ensure Saturn’s moons – in particular Enceladus, with its subsurface ocean and signs of hydrothermal activity – remain pristine for future exploration. The spacecraft’s fateful dive is the final beat in the mission’s Grand Finale, 22 weekly dives, which began in late April, through the gap between Saturn and its rings. No spacecraft has ever ventured so close to the planet before. The mission’s final calculations predict loss of contact with the Cassini spacecraft will take place on September 15 at 7:55 a.m. EDT (11:55 UTC; translate to your time zone). Cassini will enter Saturn’s atmosphere approximately one minute earlier, at an altitude of about 1,190 miles (1,915 km) above the planet’s estimated cloud tops (the altitude where the air pressure is 1-bar, equivalent to sea level on Earth).
For the next couple of days, as Saturn looms ever larger, Cassini expects to take a last look around the Saturn system, snapping a few final images of the planet, features in its rings, and the moons Enceladus and Titan. The final set of views from Cassini’s imaging cameras is scheduled to be taken and transmitted to Earth on Thursday, September 14. If all goes as planned, images will be posted to the Cassini mission website beginning around 11 p.m. EDT (03:00 UTC on September 15). The unprocessed images will be available at:
saturn.jpl.nasa.gov/galleries/raw-images
Live mission commentary and video from JPL Mission Control will air on NASA Television from 7 to 8:30 a.m. EDT (11 to 12:30 UTC; translate to your time zone) on September 15. A post-mission news briefing from JPL is currently scheduled for 9:30 a.m. EDT (13:30 UTC), also on NASA TV.
Click here to go to NASA TV: www.nasa.gov/nasalive
A new NASA e-book, The Saturn System Through the Eyes of Cassini, showcasing compelling images and key science discoveries from the mission, is available here, for free download, in multiple formats.
An online toolkit of information and resources about Cassini’s Grand Finale and final plunge into Saturn is available here: saturn.jpl.nasa.gov/mission/grand-finale/overview/
Follow the Cassini spacecraft’s plunge on social media using #GrandFinale, or visit:
twitter.com/CassiniSaturn
www.facebook.com/NASACassini
During its dive into the atmosphere, the spacecraft’s speed will be approximately 70,000 miles (113,000 km) per hour. The final plunge will take place on the day side of Saturn, near local noon, with the spacecraft entering the atmosphere around 10 degrees north latitude.
When Cassini first begins to encounter Saturn’s atmosphere, the spacecraft’s attitude control thrusters will begin firing in short bursts to work against the thin gas and keep Cassini’s saucer-shaped high-gain antenna pointed at Earth to relay the mission’s precious final data. As the atmosphere thickens, the thrusters will be forced to ramp up their activity, going from 10 percent of their capacity to 100 percent in the span of about a minute. Once they are firing at full capacity, the thrusters can do no more to keep Cassini stably pointed, and the spacecraft will begin to tumble.
When the antenna points just a few fractions of a degree away from Earth, communications will be severed permanently. The predicted altitude for loss of signal is approximately 930 miles (1,500 kilometers) above Saturn’s cloud tops. From that point, the spacecraft will begin to burn up like a meteor. Within about 30 seconds following loss of signal, the spacecraft will begin to come apart; within a couple of minutes, all remnants of the spacecraft are expected to be completely consumed in the atmosphere of Saturn.
Due to the travel time for radio signals from Saturn, which changes as both Earth and the ringed planet travel around the Sun, events currently take place there 86 minutes before they are observed on Earth. This means that, although the spacecraft will begin to tumble and go out of communication at 6:31 a.m. EDT (3:31 a.m. PDT) at Saturn, the signal from that event will not be received at Earth until 86 minutes later.
Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said:
"The spacecraft’s final signal will be like an echo. It will radiate across the solar system for nearly an hour and a half after Cassini itself has gone. Even though we’ll know that, at Saturn, Cassini has already met its fate, its mission isn’t truly over for us on Earth as long as we’re still receiving its signal."
Cassini’s last transmissions will be received by antennas at NASA’s Deep Space Network complex in Canberra, Australia.
Cassini is set to make groundbreaking scientific observations of Saturn, using eight of its 12 science instruments. All of the mission’s magnetosphere and plasma science instruments, plus the spacecraft’s radio science system, and its infrared and ultraviolet spectrometers will collect data during the final plunge.
Chief among the observations being made as Cassini dives into Saturn are those of the Ion and Neutral Mass Spectrometer (INMS). The instrument will directly sample the composition and structure of the atmosphere, which cannot be done from orbit. The spacecraft will be oriented so that INMS is pointed in the direction of motion, to allow it the best possible access to oncoming atmospheric gases.
Bottom line: Click here for links to the last few raw images gathered by Cassini prior to its plunge into Saturn on September 15, 2017, and to learn how to follow the mission’s end online.
earthsky.org/space/cassini-finale-sept-15-2017-how-to-follow-online?mc_cid=a2c28121ad&mc_eid=9b2daed519
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Sept 14, 2017 13:19:22 GMT -6
Post by swamprat on Sept 14, 2017 13:19:22 GMT -6
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Sept 15, 2017 10:39:55 GMT -6
Post by swamprat on Sept 15, 2017 10:39:55 GMT -6
RIP, Cassini: Historic Mission Ends with Fiery Plunge into SaturnBy Calla Cofield, Space.com Senior Writer September 15, 2017
Members of the Cassini team and other JPL employees watch the final minutes of the Cassini mission, next to a full-scale model of the spacecraft. Credit: Calla Cofield/Space.com
NASA received its last data transmission from the Cassini spacecraft at 4:55:46 a.m. PDT (7:55:46 a.m. EDT, 1146 GMT) today (Sept. 15), before losing contact with the probe as it hurtled into Saturn's atmosphere. It was a fiery grand finale for the probe, which spent 13 years orbiting the ringed planet. NASA officials expect that Cassini broke apart about 45 seconds after that final transmission, due to the intense friction and heat generated by the fall.
"I hope you're all ... deeply proud of this amazing accomplishment," Earl Maize, the Cassini program manager, said to the mission team after the spacecraft signal was lost. "Congratulations to you all. This has been an incredible mission, an incredible spacecraft, and you're all an incredible team. I'm going to call this the end of mission."
www.space.com/38167-cassini-spacecraft-plunges-into-saturn.html
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Sept 15, 2017 19:41:24 GMT -6
Post by swamprat on Sept 15, 2017 19:41:24 GMT -6
‘OK. Let’s do it!’ An oral history of how NASA’s Cassini mission to Saturn came to be By Deborah Netburn Sep 12, 2017
In the predawn hours Friday, NASA’s Cassini spacecraft will make a suicide dive into Saturn’s atmosphere, vaporizing like a tiny meteor in the vast Saturnian sky.
It will be a fiery end for a spacecraft built and flown by the Jet Propulsion Laboratory that has spent the last 13 years exploring the ringed planet and its many moons. Cassini set off for Saturn on Oct. 15, 1997, and spent seven years looping around the solar system before it finally reached its destination. Since then, the two-story spacecraft has revealed that ocean worlds are more common in our solar system than anyone knew, watched moonlets form in Saturn’s rings and found conditions suitable for life on two of the planet’s moons.
The Cassini mission has been an unequivocal success — but its fate was not always certain.
Originally conceived in the early 1980s, Cassini and its companion Huygens lander contended with debilitating budget cuts, narrowly escaped cancellation more than once, and faced last-minute attempts to ground the spacecraft out of fear that a launch mishap would cause radioactive plutonium to rain down on Earth.
Cassini followed in the footsteps of the Voyager and Galileo missions, becoming the last big spacecraft to explore the outer solar system. This is the story of how it got off the ground, told by the people who were there.
Engineers and technicians at JPL work to complete the stacking assembly of the Cassini spacecraft in 1996. (Ken Lubas / Los Angeles Times)
Linda Spilker, Cassini mission project scientist at JPL: "Had we not had Voyager, I don’t think we would have had Cassini. The whole reason we wanted to go back to Saturn was because of what Voyager was not able to do there."
Bonnie Buratti, principal scientist and supervisor of the Comets, Asteroids, and Satellites Group at JPL: "Voyager had done a reconnaissance of the Saturnian system and there were all these great discoveries. There was Titan, which looked kind of like an Earth in deep freeze. Enceladus looked like it was covered in snow. And there was Iapetus, a moon with one half as dark as tar and the other half basically as bright as snow. So there were all these mysteries."
Andy Ingersoll, planetary scientist at Caltech: "Voyager had also done a lot to reveal the detailed structure of the rings. It was clear that the closer we got and the more time we spent there, it was going to be really fascinating. And it turned out it was."
Hunter Waite, director of planetary mass spectrometry at Southwest Research Institute: "It’s like the onion that you peel back. Voyager scratched the surface — it pulled back the first layer."
Spilker: "With the Voyager 1 flyby in 1980, we flew close to Titan and found that with the cameras and instruments we had, we couldn’t see through the haze to the surface."
Toby Owen, planetary scientist at the University of Hawaii: "What lay beneath that smog? Speculation ranged from a global ocean of ethane to a rugged landscape carved out by precipitating hydrocarbons, to a nondescript, gooey surface resembling a refrozen chocolate ice cream dessert."
Daniel Gautier, planetary scientist at the Paris Observatory at Meudon: "Voyager revealed that the main component of the Titan atmosphere was molecular nitrogen, with a few percent of methane. Laboratory experiments had shown that an irradiated mixture of nitrogen and methane produces complex organic molecules and compounds, including some that are present in living systems on the Earth."
Ingersoll: "Toby Owen gets a lot of credit for pushing the Cassini mission, especially the interest in Titan as an analogue of Earth in its early days. Before we had an oxygen atmosphere, before we had life, we could have had a similar atmosphere to Titan’s."
A diagram of the Cassini spacecraft and Huygens probe. (NASA Jet Propulsion Laboratory)
The plutonium scare Earl Maize, Cassini program manager at JPL: "Saturn has about 1/100th the sunlight as we have on Earth. Solar panels would work, but they would be so inefficient that it would just be ridiculous. In the outer solar system, plutonium is the best power source."
Waite: "There were a lot of people protesting because we had plutonium as a fuel. They were trying to lobby against us being able to launch because we were going to kill people and so forth."
Webster: "The theory was that we were going to release radioactive materials into the atmosphere if there was a launch failure. You can make bombs out of plutonium 235, but that’s a different isotope from what we used. We used plutonium 238 and we made into an oxide so it’s not a bomb. It’s not fissionable material. But it is radioactive, so it’s hot. We take the heat and put it into a thermocouple and make it into electrical energy. It’s exactly like a solar panel. It just happens to be a radioactive solar panel."
Waite: "Plutonium is dangerous stuff but the way it is processed and used in space is pretty darn safe for the most part."
Buratti: "Cassini scientists were very confident that the plutonium was packaged in a way that it would not escape the spacecraft in the case of a launch vehicle failure. The conservative engineers at JPL did a number of studies showing this. Many of the Cassini scientists were active in the antiwar and nuclear disarmament movement, so we didn't take these concerns lightly.
Nevertheless there were a lot of protests and a movement to stop the launch. JPL had a whole office to address the public's concerns at that time. I do remember the protesters: They were few but vociferous. They were mainly at Cape Canaveral, but I seem to remember a few stragglers at JPL as well."
Webster: "Our project manager at the time, Richard Spehalski, was on '60 Minutes' right before we launched. He basically looked at the '60 Minutes' guys and said, 'My grandchildren are watching the launch. If I was worried about this, would I have my grandchildren watching the launch?' "
Epilogue There would be more nail-biting moments to come over the 20 years Cassini spent in space: a harrowing 90-minute engine burn to enter Saturn’s orbit, Huygens’ 2.5-hour descent to Titan — “I’m still trembling with fear from that time,” said Ip — and, just a few weeks ago, the spacecraft’s first dip into Saturn’s atmosphere. Cassini sailed through these hurdles, and many more.
Read more: www.latimes.com/science/la-sci-cassini-oral-history-20170912-htmlstory.html
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Aug 4, 2018 14:16:56 GMT -6
Post by auntym on Aug 4, 2018 14:16:56 GMT -6
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uma
New Member
Posts: 5
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SATURN
Aug 7, 2018 6:16:04 GMT -6
Post by uma on Aug 7, 2018 6:16:04 GMT -6
NIce and informative posts! Thank you guys!
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Oct 29, 2018 12:21:46 GMT -6
Post by auntym on Oct 29, 2018 12:21:46 GMT -6
mysteriousuniverse.org/2018/10/saturns-moon-dione-covered-in-strange-unexplained-stripes/ Saturn’s Moon Dione Covered in Strange Unexplained Stripesby Sequoyah Kennedy / mysteriousuniverse.org/author/skennedy/October 29, 2018 Saturn has 62 moons. Of those, 53 have been formally named while nine others are such recent discoveries that they haven’t yet received an official name. Titan, the largest of Saturn’s moons, is more massive than the planet Mercury and has a nitrogen-rich atmosphere similar to Earth’s. Enceladus, another moon, likely has an internal ocean as evidenced by the volcanoes of ice that plume from its surface into space and fall back to the surface as snow. Complex organic molecules have been detected in Enceladus, making it one of the prime candidates for finding extraterrestrial life in our solar system. There may be only nine formally recognized planets in our solar system, but there are 181 moons orbiting those planets, each with their own complexities and unique mysteries. Saturn’s moon Dione is one of those mysteries. Dione is smaller than Earth’s moon, and exists in orbital resonance with Enceladus, meaning that it completes one orbit of Saturn for every two completed by Enceladus. This orbital resonance is likely the source of the geologic heat found in Enceladus, which reveals itself in the form of Enceladus’s dramatic ice volcanoes. Despite being smaller than Earth’s moon, Dione proves that size isn’t everything in terms of astronomical weirdness. Data from Cassini shows that, along with an orbital relationship, Dione shares other similarities with Enceladus, most notably the presence of an interior ocean., but Dione isn’t simply a twin of Enceladus. According to a new study published in journal Geophysical Research Letters, the small moon has a mystery all its own. Streaking across its surface are bright white stripes unlike anything else seen in the solar system, and so far scientists don’t know what they are. Saturn's moon DioneDione. Image Credit: NASA/JPL-Caltech/Space Science Institute Scientists have ruled out geologic causes for the stripes like tectonic activity. Instead, they say that whatever the stripes are made of, they’re likely draped across the surface like snow. What’s strange is how they’re draped. Other bodies in the solar system, including Saturn’s moon Rhea, show bright lines on the surface but none as straight and seemingly intentional as the lines on Dione. The lines are between six and sixty two miles long and three miles wide and perfectly straight. Not only are they perfectly straight, but they run parallel to Dione’s equator, a trait that scientists say is very unusual. They are unbroken, which scientists take to mean that they are a relatively new phenomenon and possibly part of an ongoing phenomenon in the Saturn system. The authors of the study say that the cause of these mysterious lines is likely due to some off world influence: We explored different ways of forming linear features on planetary surfaces and favor the draping of exogenic material across a planetary surface by encounters with either Saturn’s rings, co‐orbital moons, or close flyby of comets. This debris may introduce materials into the Dione system that could contribute to creating a more habitable Dione. DioneOne of Cassini’s final images of Dione. Image Credit: NASA/JPL-Caltech/Space Science Institute Recently, scientists demonstrated that one of the building blocks of life here on earth was probably formed in space and deposited here on Earth. With a liquid water interior and constant depositing of off-world material on Dione, it seems possible that some strange chemistry could make its way into the underground sea and begin the process of life. Of course, such life would be likely be microscopic and completely outside our ability to study it for many years to come. This does show that, once again, the more we learn about our corner of space, the more mysteries we uncover. mysteriousuniverse.org/2018/10/saturns-moon-dione-covered-in-strange-unexplained-stripes/
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Nov 28, 2018 12:34:17 GMT -6
Post by swamprat on Nov 28, 2018 12:34:17 GMT -6
A billionaire’s plan to search for life on EnceladusBy Paul Scott Anderson in SPACE | November 27, 2018
Russian entrepreneur and physicist Yuri Milner wants to send a probe back to Saturn’s ocean moon Enceladus, to search for evidence of life there. NASA wants to help him.
Cassini spacecraft image from 2010 of Saturn’s moon Enceladus. The moon is backlit, with its dark outline crowned by glowing jets – aka geysers – emanating from Enceladus’ south polar region. Image via NASA/JPL/SSI.
Saturn’s moon Enceladus is very small – only about 310 miles (500 kilometers) across – but it may hold clues to one of the biggest mysteries of all time – are we alone? Beneath the icy crust lies a global salty ocean, not too different from Earth’s oceans. Could that ocean contain life of some kind? That is a question that many scientists – and the public alike – would like to find an answer for. Enceladus, however, is very far away and planetary missions are expensive – but there may be an ideal solution.
Billionaire entrepreneur and physicist Yuri Milner wants to send a private mission back to this intriguing world, and NASA wants to help him. This incredible idea was first reported in New Scientist on November 8, 2018 (please note this article is behind a paywall). It was then reported by Gizmodo the same day.
Agreements signed by NASA and Milner’s non-profit Breakthrough Starshot foundation in September show that the organisations are working on scientific, technical and financial plans for the ambitious mission. NASA has committed over $70,000 to help produce a concept study for a flyby mission. The funds won’t be paid to Breakthrough but represent the agency’s own staffing costs on the project.
Enceladus is a very small moon, but it has a global ocean beneath its icy crust. Image via NASA/JPL-Caltech.
Breakthrough Initiatives, part of Milner’s non-profit Breakthrough Starshot Foundation, would lead and pay for the mission, with consultation from NASA. The board of Breakthrough Initiatives includes billionaires Yuri Milner and Mark Zuckerberg, and the late physicist Stephen Hawking. Breakthrough Initiatives has been studying various mission concepts for space exploration, including a solar sail to nearby stars, advancing the technology to discover other Earth-like planets and sending out a direct message, similar to the previous Arecibo message, specifically to try and catch the attention of aliens.
Enceladus has become a prime target in the search for extraterrestrial life in our solar system, since its subsurface ocean is thought to be quite similar to oceans on Earth, thanks to data from the Cassini mission, which orbited Saturn from 2004 until September of last year. Scientists already know it is salty and there is evidence for geothermal activity on the ocean floor, such as “smoker” volcanic vents on the bottom of oceans on Earth. Such geothermal vents – at least on Earth – are oases for a wide variety of ocean life despite the darkness and cold temperatures away from the vents.
Cassini also investigated the plumes of Enceladus – huge “geysers” of water vapor erupting through cracks in the surface at the south pole of Enceladus. Cassini flew right through some of them, analyzing their composition, and found they contain water vapor, ice particles, complex organic molecules and salts. Cassini wasn’t capable of finding life directly, but it did find valuable clues and hints that there may well be something alive in that alien ocean, even if only microbes.
Earlier this year, New Scientist also reported that there may already be some tentative evidence for microbes in Enceladus’s ocean. Cassini detected traces of methane in the water vapor plumes, and when scientists tested computer models of conditions in the ocean, they found that microbes that emit methane after combining hydrogen and carbon dioxide – called methanogens – could easily survive there. According to Chris McKay at NASA’s Ames Research Center in Moffett Field, California:
"This [team] has taken the first step to showing experimentally that methanogens can indeed live in the conditions expected on Enceladus."
The scientists found that the microbes were able to thrive at temperatures and pressures likely found in Enceladus’s oceans, ranging from 0 to 90 degrees Celsius, and up to 50 Earth atmospheres. They also found that olivine minerals, thought to exist in the moon’s core, could be chemically broken down to produce enough hydrogen for methanogens to thrive.
Another proposed return mission to Enceladus is the Enceladus Life Finder (ELF), which would orbit Saturn and make repeated passes through the plumes – like Cassini, but with updated instruments. Image via Jonathan Lunine.
Another proposed return mission to Enceladus is the Enceladus Life Finder (ELF), which would orbit Saturn and make repeated passes through the plumes – like Cassini, but with updated instruments that could even test whether any amino acids found have predominately left or right-handed structures. (Life on Earth predominately creates left-handed forms, and scientists think that life elsewhere will also favor one form over the other instead of a random mixture as would occur from abiotic chemistry.)
Cassini wasn’t designed to detect life directly, but on a future mission – such as the one proposed – a mass spectrometerwould be able to detect carbon isotope ratios unique to living organisms, as well as other potential “biomarkers” of methanogens, including lipids and hydrocarbons.
Bottom line: Scientists are eager to return to Enceladus to learn more about its intriguing subsurface ocean. The new plan by billionaire Yuri Milner, with NASA’s assistance, may be the best bet to go back and see if anything is swimming in those mysterious alien waters.
earthsky.org/space/billionaire-yuri-milner-nasa-plan-life-search-enceladus
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SATURN
Jul 4, 2019 9:17:04 GMT -6
Post by Deleted on Jul 4, 2019 9:17:04 GMT -6
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SATURN
Oct 13, 2021 18:25:19 GMT -6
Post by auntym on Oct 13, 2021 18:25:19 GMT -6
www.ufosightingsfootage.uk/2021/10/motherships-parked-insde-saturns-rings.htmlMothership's Parked Insde Saturn's Rings Photos Taken By VoyagerSuch report's not long ago was absolutely laughable, actually some people still so laugh at these allegations because of the lack of knowledge or because it's somehow funny?Even though we've had UFO disclosure, I suppose it's still hard for some people to let go of familiar structures and things (like a safety blanket) and see the universe as it is. Credit: Voyager Wikipedia/Aboluowang News/UFO Sighting's Footage/UFO News/Canva.Dr Norman Bergrun, a mysterious figure who is said to have been employed at Nasa's Ames Research Center, reportedly claimed that gigantic UFOs are hiding in the rings of Saturn. The Sun / www.thesun.co.uk/tech/4044454/former-nasa-engineer-claims-massive-alien-motherships-are-lurking-inside-the-rings-of-saturn/It's teaming with Aliens, we just so happen to inhabit this area of space and in 300 yrs, we will have space stations the likes of which are beyond anything that we can comprehend at the moment due to technological capabilities. We're only capable of sending certain thing's into space at the moment but wait while that ramps up with advances in technological capabilities and the development of sophisticated materials or smart materials. Time will reveal all. Credit: Voyager.www.ufosightingsfootage.uk/2021/10/motherships-parked-insde-saturns-rings.html
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