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Ringmakers of Saturn?
#34
Farewell Cassini: Saturn spacecraft makes fiery, final dive (Update)
September 15, 2017 by Marcia Dunn

[Image: farewellcass.jpg]
This July 23, 2008 image made available by NASA shows the planet Saturn, as seen from the Cassini spacecraft. After a 20-year voyage, Cassini is poised to dive into Saturn on Friday, Sept. 15, 2016. (NASA/JPL/Space Science Institute via AP)
NASA's Cassini spacecraft disintegrated in the skies above Saturn on Friday in a final, fateful blaze of cosmic glory, following a remarkable journey of 20 years.


Confirmation of Cassini's expected demise came about 7:55 a.m. EDT. That's when radio signals from the spacecraft—its last scientific gifts to Earth—came to an abrupt halt. The radio waves went flat, and the spacecraft fell silent.
Cassini actually burned up like a meteor 83 minutes earlier as it dove through Saturn's atmosphere, becoming one with the giant gas planet it set out in 1997 to explore. But it took that long for the news to reach Earth a billion miles away.
The only spacecraft to ever orbit Saturn, Cassini showed us the planet, its rings and moons up close in all their splendor. Perhaps most tantalizing, ocean worlds were unveiled on the moons Enceladus and Titan, which could possibly harbor life.
Dutiful to the end, the Cassini snapped its last photos Thursday and sampled Saturn's atmosphere Friday morning as it made its final plunge. It was over in a minute or two.
Program manager Earl Maize made the official pronouncement:
"This has been an incredible mission, an incredible spacecraft and you're all an incredible team," Maize said. "I'm going to call this the end of mission."
[Image: 2-farewellcass.jpg]
Flight director Julie Webster reacts in mission control at NASA's Jet Propulsion Laboratory after confirmation of Cassini's demise Friday, Sept. 15, 2017, in Pasadena , Calif. Cassini disintegrated in the skies above Saturn early Friday, following a remarkable journey of 20 years. (AP Photo/Jae C. Hong, Pool)
Flight controllers wearing matching purple shirts stood and embraced and shook hands. Project scientist Linda Spilker also had a purple handkerchief to wipe away tears.
"It felt so much like losing a friend," she told reporters a couple of hours later.
More than 1,500 people, many of them past and present team members, had gathered at California's Jet Propulsion Laboratory for what was described as both a vigil and celebration. Even more congregated at nearby California Institute of Technology, which runs the lab for NASA.
The spacecraft tumbled out of control while plummeting at more than 76,000 mph (122,000 kph). Project officials invited ground telescopes to look for Cassini's last-gasp flash, but weren't hopeful it would be spotted against the vast backdrop of the solar system's second largest planet. The radio link actually held on a half-minute longer than expected.
"There are times in this world when things just line up, when everything is just about perfect. A child's laugh, a desert sunset and this morning. It just couldn't have been better," said Maize. "Farewell, faithful explorer."
[Image: 1-farewellcass.jpg]
This May 4, 2014 image made available by NASA shows the persistent hexagonal cloud pattern on Saturn's north pole, as seen from the Cassini spacecraft. The hexagon is similar to Earth's polar vortex, which has winds blowing in a circular pattern around the polar region, and is nearly 25,000 kilometers (15,000 miles) across. Nearly four Earths could fit inside it. (NASA/JPL-Caltech/Space Science Institute via AP)
This Grand Finale, as NASA called it, came about as Cassini's fuel tank started getting low after 13 years exploring the planet. Scientists wanted to prevent Cassini from crashing into Enceladus or Titan—and contaminating those pristine worlds. And so in April, Cassini was directed into the previously unexplored gap between Saturn's cloud tops and the rings. Twenty-two times, Cassini entered the gap and came out again. The last time was last week.


Read more at: https://phys.org/news/2017-09-latest-nasa-cassini-spacecraft-saturn.html#jCp
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Cassini departed Earth in 1997 and arrived at the sixth planet from our sun in 2004. The hitchhiking European Huygens landed on big moon Titan in 2005. Nothing from Earth has landed farther. Three other spacecraft previously flew past Saturn, but Cassini was the only one to actually circle the planet.
In all, Cassini collected more than 453,000 images and traveled 4.9 billion miles. It was an international endeavor, with 27 nations taking part. The final price tag was $3.9 billion.
European space officials joined their U.S. colleagues to bid Cassini farewell. Seventeenth-century astronomers supplied the spacecraft names: Italy's Giovanni Domenico Cassini, who discovered four moons and the wide division in Saturn's rings, and Holland's Christiaan Huygens, who spotted the first and biggest moon, Titan.
The latest count is 62 moons, six of them found by the spacecraft Cassini.
[url=https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2017/3-farewellcass.jpg][Image: 3-farewellcass.jpg]

This Wednesday, Sept. 13, 2017 image taken using the CL1 and RED filters and made available Thursday by NASA shows Saturn's rings, as seen from the Cassini spacecraft. NASA's Cassini spacecraft at Saturn is closing in on its fiery finish, …more
There were some lighthearted touches during the morning. At one point in the broadcast, NASA played a video clip of the Cassini Virtual Singers, spacecraft team members who belted out, "Tonight, tonight, we take the plunge tonight ..." to the music from "West Side Story." Parties were planned for the teams throughout the weekend, complete with Champagne.
Scientists are already eager to go back and delve into the wet, wild worlds of Enceladus and Titan. Proposals are under consideration by NASA, but there's nothing official yet. In the meantime, NASA plans sometime in the 2020s to send an orbiter and lander to Europa, a moon of Jupiter believed to have a global ocean that might be compatible for life.
"These (water) worlds that they found, we never knew were there, are changing how we think about life itself," said NASA's science mission director, Thomas Zurbuchen. "And so for me, that's why it's truly a civilization-scale mission, one that will stand out among other missions, anywhere."
Julie Webster, spacecraft operations manager for Cassini, said she's been blasting the Moody Blues' "Your Wildest Dreams" in her car the last few days.
"This has truly been beyond my wildest dreams."
[Image: 4-farewellcass.jpg]
Engineer Mar Vaquero monitors the status of NASA's Cassini spacecraft as it enters the atmosphere of Saturn in mission control at NASA's Jet Propulsion Laboratory, Friday, Sept. 15, 2017, in Pasadena, Calif. Cassini disintegrated in the …more

[Image: 5-farewellcass.jpg]
This image made available by NASA shows the moon Enceladus and the edge of Saturn as seen from the Cassini spacecraft on its descent towards the planet on Wednesday, Sept. 13, 2017. The probe disintegrated in the skies above Saturn early …more
[Image: 6-farewellcass.jpg]
This Wednesday, Sept. 13, 2017 image taken using the CL1 and RED filters and made available Thursday by NASA shows Saturn's moon Titan, as seen from the Cassini spacecraft. NASA's Cassini spacecraft at Saturn is closing in on its fiery …more
[Image: 7-farewellcass.jpg]
This Feb. 17, 2005 image made available by NASA shows plumes of water ice and vapor from the south polar region of Saturn's moon Enceladus. The activity is understood to originate from the moon's subsurface ocean of salty liquid water, …more
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This May 21, 2015 image made available by NASA shows Saturn's moon Dione crossing the face of the gas giant, in a phenomenon astronomers call a transit. Transits play an important role in astronomy and can be used to study the orbits of …more
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This July 19, 2013 image made available by NASA shows Saturn's rings and planet Earth, center right, as seen from the Cassini spacecraft. (NASA/JPL-Caltech/Space Science Institute via AP)
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Flight director Julie Webster gets emotional in mission control at NASA's Jet Propulsion Laboratory after confirmation of Cassini's demise Friday, Sept. 15, 2017, in Pasadena, Calif. Cassini disintegrated in the skies above Saturn early …more
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Engineer Nancy Vandermay, left, wipes her tears in mission control at NASA's Jet Propulsion Laboratory after confirmation of Cassini's demise Friday, Sept. 15, 2017, in Pasadena , Calif. Cassini disintegrated in the skies above Saturn early …more
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IO manager Luis Morales monitors the status of NASA's Cassini spacecraft in mission control at NASA's Jet Propulsion Laboratory, Friday, Sept. 15, 2017, in Pasadena, Calif. Cassini disintegrated in the skies above Saturn early Friday, …more

[Image: 13-farewellcass.jpg]
Project manager Earl Maize, center, shakes hands with Bill Heventhal in mission control at NASA's Jet Propulsion Laboratory, Friday, Sept. 15, 2017, in Pasadena, Calif. after confirmation of Cassini's demise. Cassini disintegrated in the …more
[Image: 14-farewellcass.jpg]
In this Oct. 31, 1996 photo made available by NASA, the newly assembled Cassini Saturn probe undergoes vibration and thermal testing at the Jet Propulsion Laboratory facilities in Pasadena, Calif. It was subjected to weeks of "shake and …more
[Image: 15-farewellcass.jpg]
Project manager Earl Maize, center, shakes hands with Bill Heventhal in mission control at NASA's Jet Propulsion Laboratory, Friday, Sept. 15, 2017, in Pasadena, Calif. after confirmation of Cassini's demise. Cassini disintegrated in the …more
[Image: 16-farewellcass.jpg]
This Wednesday, Sept. 13, 2017 image made available by NASA on Friday, Sept. 15, 2017 shows the atmospheric haze on the moon Titan as seen from the Cassini spacecraft on its descent towards Saturn. The probe disintegrated in the skies above …more
[Image: 1x1.gif] Explore further: NASA's Cassini spacecraft at Saturn nears fiery finale
More information: NASA: saturn.jpl.nasa.gov/


Read more at: https://phys.org/news/2017-09-latest-nasa-cassini-spacecraft-saturn.html#jCp
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#35
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much more at link

http://newsroom.ucla.edu/releases/intens...sts-report
Intense storms batter Saturn’s largest moon, UCLA scientists report
Extreme methane rainstorms appear to have a key role in shaping Titan’s icy surface


Quote:The storms create massive floods in terrain that are otherwise deserts. 
“The most intense methane storms in our climate model dump at least a foot of rain a day, 

Previous models have shown that liquid methane
generally concentrates on Titan’s surface at higher latitudes.

But no previous study had investigated the behavior of extreme rainfall events
that might be capable of triggering major sediment transport and erosion,
or shown their connection to surface observation.

They found that while rain mostly accumulates near the poles,
where Titan’s major lakes and seas are located, t
he most intense rainstorms occur near 60 degrees latitude —
precisely the region where alluvial fans are most heavily concentrated.
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#36
Saturn's radiation belts: A stranger to the solar wind
October 30, 2017



[Image: saturnsradia.jpg]
Credit: MPS, Imge of Saturn: NASA/JPL/Space Science Institute
The radiation belts of Earth and Saturn differ more strongly than previously assumed. In these belts, very energetic particles, such as electrons and protons, move around the planet at high velocities - captured by its magnetic field. In the case of the Earth, the solar wind, a current of charged particles from the Sun varying in strength, controls the intensity of the radiation belt both directly and indirectly. The radiation belts of Saturn, however, develop completely independently of the solar wind and are instead decisively influenced by the gas giant's moons. These results are published today in the journal Nature Astronomy by a group of researchers from the Max Planck Institute for Solar System Research (MPS) in Germany co-leading the most comprehensive study on the subject to date. Key to the new findings are measurements of the MIMI-LEMMS instrument aboard NASA's Cassini space probe, which explored the Saturn system for more than 13 years before its dive into the planet on the 15th of September this year.





The activity of the Sun – and with it the strength of the solar wind – follows an eleven-year cycle. Investigating the long term influence of the solar wind on a planet's radiation belts therefore requires patience – and space missions of a considerable length. "If Cassini's mission to the Saturn system had ended after four years, as initially planned, we would never have been able to achieve these results," explains Dr. Elias Roussos of the MPS. Fortunately, the mission was extended several times. The Magnetospheric Imaging Instrument (MIMI) with its high energy particle detector (LEMMS) on board Cassini was therefore able to record the distribution of charged particles in the vicinity of Saturn over a period of time that includes a complete solar cycle. "Such extensive in-situ data on the radiation belts of a planet are otherwise only available for Earth," says MPS researcher Dr. Norbert doody-man, who heads the MIMI-LEMMS team.
As data from Cassini show, Saturn's proton radiation belts are gigantic: they reach from the planet's innermost ring to the orbit of the moon Tethys – and thus more than 285,000 kilometers into space. A decisive difference to Earth: while our moon is located far beyond the limits of the magnetosphere and the radiation belts, Saturn's radiation belts contain several of its satellites, such as the large moons Janus, Mimas, and Enceladus. "Saturn's moons influence the radiation belts decisively," says doody-man. They act as a kind of boundary wall on very energetic particles, particularly protons. Any protons diffusing further inwards from their place of origin are absorbed and thus stopped when they interact with a moon. "This creates areas in the radiation belt which are completely isolated from one another," says Roussos. Unlike Saturn, particles arising outside Earth's radiation belts may travel inward and replenish its content.
On Earth, the high-energy particles that form the radiation belts have two origins. Some are provided directly by the solar wind. Others result from incident protons of extreme energy originating from our Galaxy, called Galactic Cosmic Rays. When Galactic Cosmic Rays reach the planet's atmosphere, it sets in motion a chain of reactions, at the end of which high-energy electrons and protons are created. Since the solar wind partially shields and thus modulates this cosmic radiation, the Sun's activity also plays a decisive role in this process.

In the Saturnian system this is different. "In the first years of the Cassini mission, we observed that the solar wind could cause dramatic changes in Saturn's magnetosphere," says Roussos. "However, this direct influence stopped abruptly at the orbit of the moon Tethys."
Nevertheless, at first everything indicated that the solar wind still helps to shape the radiation belts – if only indirectly: the first years of the Cassini mission coincided with a decline in the Sun's activity; the intensity of the radiation belts increased as expected. In the period from 2010 to 2012, however, there was a rapid intensity drop that could not be attributed to the solar wind modulation of Galactic Cosmic Rays, which changes on much longer timescales. And also solar storms, violent eruptions of particles and radiation from the Sun, could not have been responsible. While time and again on Earth such events cause a sudden decline of intensity, extensive simulations performed by the researchers show, that this effect can also not explain the year-long decrease witnessed by Cassini.
Rather, the scientists suspect that extreme ultraviolet radiation from the Sun may be responsible. This radiation can locally heat the atmosphere of a planet. The resulting turbulent winds transmit this information to the ionosphere which is "anchored" to the magnetosphere through the planet's magnetic field. As a result, the protons in the radiation belts spread out much more efficiently than usual. On their way, they encounter Saturn's moons and are absorbed: the intensity of the radiation belts thereby decreases significantly. "We observe that the intensity drop in the proton radiation belts of Saturn coincides exactly with strong changes in the EUV radiation from the Sun," Roussos describes the new results. It is therefore possible that while the solar wind has no impact on the radiation belts, the Sun still may.
"Our analyses also remind us how strongly the properties of the radiation belts depend on the structure of the particular planet system, that is, the position and number of moons for the case of Saturn", says Roussos. This knowledge could also be helpful for a glance beyond the edge of the solar system: if in the future the radiation belts of an exoplanet could be detected, these data could also indirectly contain information about the system's properties and structure.
[Image: 1x1.gif] Explore further: New Transient Radiation Belt Discovered at Saturn
More information: P. Kollmann, E. Roussos, A. Kotova, C. Paranicas and N. doody-man, The evolution of Saturn's radiation belts modulated by changes in radial diffusion, Nature Astronomy, 30 October 2017, nature.com/articles/doi:10.1038/s41550-017-0287-x 
Journal reference: Nature Astronomy [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Max Planck Society



Read more at: https://phys.org/news/2017-10-saturn-bel...r.html#jCp



Jupiter's X-ray auroras pulse independently

October 30, 2017

[Image: jupiter.jpg]
This is Jupiter's Great Red Spot in 2000 as seen by NASA's Cassini orbiter. Credit: NASA/JPL/Space Science Institute
Jupiter's intense northern and southern lights pulse independently of each other according to new UCL-led research using ESA's XMM-Newton and NASA's Chandra X-ray observatories.


The study, published today in Nature Astronomy, found that very high-energy X-ray emissions at Jupiter's south pole consistently pulse every 11 minutes. Meanwhile those at the north pole are erratic: increasing and decreasing in brightness, independent of the south pole.
This behaviour is distinct from Earth's north and south auroras which broadly mirror each other in activity. Other similarly large planets, such as Saturn, do not produce any detectable X-ray aurora, which makes the findings at Jupiter particularly puzzling.
"We didn't expect to see Jupiter's X-ray hot spots pulsing independently as we thought their activity would be coordinated through the planet's magnetic field. We need to study this further to develop ideas for how Jupiter produces its X-ray aurora and NASA's Juno mission is really important for this," explained lead author, William Dunn (UCL Mullard Space Science Laboratory, UK and the Harvard-Smithsonian Center for Astrophysics, USA).
Since arriving at Jupiter in 2016, the Juno mission has been re-writing much of what is known about the giant planet, but the spacecraft does not have an X-ray instrument on board. To understand how the X-ray aurora are produced, the team hope to combine the X-ray aurora information gathered using XMM-Newton and Chandra with data collected by Juno as it explores the regions producing Jupiter's aurora.
"If we can start to connect the X-ray signatures with the physical processes that produce them, then we can use those signatures to understand other bodies across the Universe such as brown dwarfs, exoplanets or maybe even neutron stars. It is a very powerful and important step towards understanding X-rays throughout the Universe and one that we only have while Juno is conducting measurements simultaneously with Chandra and XMM-Newton," said William Dunn.
One of the theories that Juno may help to prove or disprove is that Jupiter's auroras form separately when the planet's magnetic field interacts with the solar wind. The team suspect that the magnetic field lines vibrate, producing waves that carry charged particles towards the poles and these change in speed and direction of travel until they collide with Jupiter's atmosphere, generating X-ray pulses.
Using the XMM-Newton and Chandra X-ray observatories in May to June 2016 and March 2007, the authors produced maps of Jupiter's X-ray emissions and identified an X-ray hot spot at each pole. Each hot spot covers an area much bigger than the surface of the earth. Studying each to identify patterns of behaviour, they found that the hot spots have very different characteristics.
"The behaviour of Jupiter's X-ray hot spots raises important questions about what processes produce these auroras. We know that a combination of solar wind ions and ions of Oxygen and Sulphur, originally from volcanic explosions from Jupiter's moon, Io, are involved. However, their relative importance in producing the X-ray emissions is unclear," explained co-author Dr Licia Ray (Lancaster University).
"What I find particularly captivating in these observations, especially at the time when Juno is making measurements in situ, is the fact that we are able to see both of Jupiter's poles at once, a rare opportunity that last occurred ten years ago. Comparing the behaviours at the two poles allows us to learn much more of the complex magnetic interactions going on in the planet's environment," concluded co-author Professor Graziella Branduardi-Raymont (UCL Space & Climate Physics).
The team hopes to keep tracking the activity of Jupiter's poles over the next two years using X-ray observing campaigns in conjunction with Juno to see if this previously unreported behaviour is commonplace.
[Image: 1x1.gif] Explore further: Jupiter's aurora presents a powerful mystery
More information: W. R. Dunn et al, The independent pulsations of Jupiter's northern and southern X-ray auroras, Nature Astronomy (2017). DOI: 10.1038/s41550-017-0262-6 
Journal reference: Nature Astronomy [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: University College London



Read more at: https://phys.org/news/2017-10-jupiter-x-...y.html#jCp
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#37
Quote:Using the XMM-Newton and Chandra X-ray observatories in May to June 2016 and March 2007, the authors produced maps of Jupiter's X-ray emissions and identified an X-ray hot spot at each pole. Each hot spot covers an area much bigger than the surface of the earth. Studying each to identify patterns of behaviour, they found that the hot spots have very different characteristics.

Gee why didn't their cobbled Juno spacecraft instruments see these?  Hmm2

Oh wait Doh   Juno is STUCK isn't it Gangup   maybe even the science instruments are "stuck" dumb also ? Shemp

Bob... Ninja Alien2
"The Light" - Jefferson Starship-Windows of Heaven Album
I'm an Earthling with a Martian Soul wanting to go Home.   
You have to turn your own lightbulb on. ©stevo25 & rhw007
Reply
#38
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The Saturn radiation belt discovery is very interesting and probably important.
I got a kick out of the scientist name on that Saturn project.


Quote:says MPS researcher Dr. Norbert doody-man

Norbert Lol doody  Toilet  man 

is his real name -- see the credits at the bottom of their paper

Hmm2

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#39
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the Titan -- rotor craft lander 

http://dragonfly.jhuapl.edu/


Quote:The Dragonfly dual-quadcopter could make multiple flights 
to explore a variety of locations on Titan. 
The dense, calm atmosphere and low gravity 
make flying an ideal means to travel to different areas of the moon – 
studies from the late-1990s onwards identified aerial mobility as a key enabler for Titan exploration, 
including helicopters, balloons, and airplanes. 

In a single flight of up to an hour, Dragonfly could fly a few 10s of km, 
farther than any planetary rover has traveled. 
With one Dragonfly hop per Titan day (16 Earth days), 
the rotorcraft could travel from its initial landing site 
to explore sites several hundred kilometers away within the planned ~2-yr mission duration. 
Although unique in its ability to fly, 
Dragonfly would spend most of the time on the surface making science measurements.

Unable to use solar power under Titan's hazy atmosphere, Dragonfly would use a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) like the Curiosity rover on Mars. Flight, data transmission, and most science operations would be planned during Titan's day (8 Earth days), with plenty of time during the Titan night to recharge.

Dragonfly's Surface and Atmospheric Science Measurements...
Sample surface material into a mass spectrometer to identify chemical components available and processes at work to produce biologically relevant compounds
Measure bulk elemental surface composition with a neutron-activated gamma-ray spectrometer
Monitor atmospheric and surface conditions, including diurnal and spatial variations, 
with meteorology sensors
Characterize geologic features via imaging
Perform seismic studies to detect subsurface activity and structure

blah blah blah

https://www.hou.usra.edu/meetings/lpsc20...r/1958.pdf
Exploring Titan's Prebiotic Organic Chemistry and Habitability 
...
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