"Кассини" !

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tnt22

https://saturn.jpl.nasa.gov/resources/7840/mighty-odysseus/
ЦитироватьMighty Odysseus



Photojournal: PIA21613

June 4, 2018

The most visually striking feature on Saturn's icy moon Tethys is Odysseus crater. An enormous impact created the crater, which is about 280 miles (450 kilometers) across, with its ring of steep cliffs and the mountains that rise at its center. Odysseus is on the leading hemisphere of Tethys (665 miles or 1,071 kilometers across). In this image, north on Tethys is up.

This view is a composite of several images taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 17, 2015, at a distance of about 28,000 miles (44,500 kilometers) from Tethys.
Спойлер
The Cassini spacecraft ended its mission on Sept. 15, 2017.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and https://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.

Credit

NASA/JPL-Caltech/Space Science Institute

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http://tass.ru/kosmos/5331544
ЦитироватьУченые нашли сложную органику в подледном океане спутника Сатурна Энцелада
28 июня, 15:34 UTC+3
 Таким образом, это небесное тело - единственный известный космический объект, кроме Земли, где есть одновременно все условия для существования жизни
 
 Спутник Сатурна Энцелад  © EPA/NASA HO  
 
ЛОНДОН, 28 июня. /ТАСС/. Международная группа ученых обнаружила сложные органические молекулы в водах океана на спутнике Сатурна Энцеладе. Открытие, по их словам, означает, что это небесное тело оказывается единственным пока известным науке космическим объектом, кроме Земли, где имеются одновременно все условия для существования жизни. Результаты исследования опубликованы в британском научном журнале Nature.
Данные, позволившие сделать такой вывод, были получены с автоматической межпланетной станции Cassini, которая занималась исследованием Сатурна и его спутников. В октябре 2015 года аппарат Cassini пролетел примерно в 50 км от поверхности южного полюса Энцелада и взял пробы для химического анализа состава его "фонтанов" - бьющих из расщелин в ледовой коре струй воды с частицами льда, которые питает находящийся под поверхностью океан.
"Энцелад в очередной раз просто поразил нас. Раньше мы находили [в космосе] лишь простейшие органические молекулы, содержавшие несколько атомов углерода, но даже это тогда казалось крайне захватывающим", - отметил участник исследования доктор Кристофер Глейн. Теперь же, по словам ученых, речь идет об органических молекулах, намного более сложных, чем аминокислоты, с массой в десять раз больше, чем у метана. "Учитывая наличие сложной органики, которая содержится в фонтанах, бьющих из водяного океана, этот спутник оказывается единственным известным нам небесным телом, кроме Земли, который одновременно удовлетворяет всем требованиям для существования жизни в той форме, в которой мы ее знаем", - сказал Глейн.
"Один из самых больших вопросов, на который стремится ответить наука, это, конечно внеземная жизнь: есть она или нет? И вот нам удалось найти место, где мы можем это проверить", - отмечает, в свою очередь, руководитель исследования Франк Постберг. "У нас есть пригодная для жизни среда, и у нас имеются средства для того, чтобы изучить ее и сказать, есть там на самом деле жизнь или нет", - добавил он.
Ранее ученые, исследовавшие археи (не имеющие ядра одноклеточные микроорганизмы) пришли к выводу, что в океане на Энцеладе могли бы выжить некоторые виды земных микроорганизмов. Кроме того, при имитации в лаборатории условий, которые, как предполагают исследователи, существуют на этом спутнике Сатурна, была выявлена возможность появления метана биологического происхождения. Ранее в пробах со станции "Кассини" был обнаружен молекулярный водород, а также следы метана.
Экспедиция Cassini началась еще в октябре 1997 года, ее основной целью было исследование Сатурна, его колец и спутников. С момента запуска Cassini преодолела 7,9 млрд километров, совершила 294 оборота вокруг Сатурна, 162 раза сближалась с его спутниками и открыла шесть новых. В сентябре 2017 года станция вошла в плотные слои атмосферы планеты-гиганта и прекратила свое существование.
"Были когда-то и мы рысаками!!!"

tnt22

ЦитироватьSounds of Saturn: Hear Radio Emissions of the Planet and Its Moon Enceladus

NASA Jet Propulsion Laboratory

Опубликовано: 9 июл. 2018 г.

New research from the up-close Grand Finale orbits of NASA's Cassini mission shows a surprisingly powerful interaction of plasma waves moving from Saturn to its moon Enceladus. Researchers converted the recording of plasma waves into a "whooshing" audio file that we can hear -- in the same way a radio translates electromagnetic waves into music. Much like air or water, plasma (the fourth state of matter) generates waves to carry energy. The recording was captured by the Radio Plasma Wave Science (RPWS) instrument Sept. 2, 2017, two weeks before Cassini was deliberately plunged into the atmosphere of Saturn.
https://www.youtube.com/watch?v=hWHLCHv4PiIhttps://www.youtube.com/watch?v=hWHLCHv4PiI (1:15)

tnt22

https://saturn.jpl.nasa.gov/news/3150/listen-sound-of-electromagnetic-energy-moving-between-saturn-enceladus/
ЦитироватьJuly 9, 2018
[SIZE=8]Listen: Sound of Electromagnetic Energy Moving Between Saturn, Enceladus[/SIZE]


NASA's Cassini spacecraft's Grand Finale orbits found a powerful interaction of plasma waves moving from Saturn to its rings and its moon Enceladus. › Full image

New research from NASA's Cassini spacecraft's up-close Grand Finale orbits shows a surprisingly powerful and dynamic interaction of plasma waves moving from Saturn to its rings and its moon Enceladus. The observations show for the first time that the waves travel on magnetic field lines connecting Saturn directly to Enceladus. The field lines are like an electrical circuit between the two bodies, with energy flowing back and forth.

Researchers converted the recording of plasma waves into a "whooshing" audio file that we can hear -- in the same way a radio translates electromagnetic waves into music. In other words, Cassini detected electromagnetic waves in the audio frequency range -- and on the ground, we can amplify and play those signals through a speaker.The recording time was compressed from 16 minutes to 28.5 seconds.

Much like air or water, plasma (the fourth state of matter) generates waves to carry energy. The Radio Plasma Wave Science (RPWS) instrument on board NASA's Cassini spacecraft recorded intense plasma waves during one of its closest encounters to Saturn.
Спойлер

NASA's Cassini spacecraft's Grand Finale orbits found a powerful interaction of plasma waves moving from Saturn to its rings and its moon Enceladus.

"Enceladus is this little generator going around Saturn, and we know it is a continuous source of energy," said Ali Sulaiman, planetary scientist at the University of Iowa, Iowa City, and a member of the RPWS team. "Now we find that Saturn responds by launching signals in the form of plasma waves, through the circuit of magnetic field lines connecting it to Enceladus hundreds of thousands of miles away."
Sulaiman is lead author of a pair of papers describing the findings, published recently in Geophysical Research Letters.

The interaction of Saturn and Enceladus is different from the relationship of Earth and its Moon. Enceladus is immersed in Saturn's magnetic field and is geologically active, emitting plumes of water vapor that become ionized and fill the environment around Saturn. Our own Moon does not interact in the same way with Earth. Similar interactions take place between Saturn and its rings, as they are also very dynamic.

The recording was captured Sept. 2, 2017, two weeks before Cassini was deliberately plunged into the atmosphere of Saturn. The recording was converted by the RPWS team at the University of Iowa, led by physicist and RPWS Principal Investigator Bill Kurth.

The GRL research is available on the American Geophysical Union's website:

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078130

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL077875

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. The RPWS instrument was built by the University of Iowa, working with team members from the U.S. and several European countries.

Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, California
818-393-6215
Gretchen.P.McCartney@jpl.nasa.gov

Dwayne Brown / JoAnna Wendel
NASA Headquarters, Washington
202-358-1726 / 202-358-1003
dwayne.c.brown@nasa.gov / joanna.r.wendel@nasa.gov
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tnt22

https://saturn.jpl.nasa.gov/resources/7845/planet-six/
ЦитироватьPlanet Six



Photojournal: PIA12567

July 16, 2018

This was Cassini's view from orbit around Saturn on Jan. 2, 2010. In this image, the rings on the night side of the planet have been brightened significantly to more clearly reveal their features. On the day side, the rings are illuminated both by direct sunlight, and by light reflected off Saturn's cloud tops.

This natural-color view is a composite of images taken in visible light with the Cassini spacecraft's narrow-angle camera at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn.
Спойлер
The Cassini spacecraft ended its mission on Sept. 15, 2017.
...

Credit

NASA/JPL-Caltech/Space Science Institute

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ЦитироватьCassiniSaturn‏Подлинная учетная запись @CassiniSaturn 15 ч. назад

#Saturn's intriguing moon Titan is completely veiled by haze. But one of our instruments was able to reveal what lies beneath. Details: https://go.nasa.gov/2NY00ie 

https://saturn.jpl.nasa.gov/resources/7846/seeing-titan-with-infrared-eyes/
ЦитироватьSeeing Titan with Infrared Eyes



Photojournal: PIA21923

July 18, 2018

These six infrared images of Saturn's moon Titan represent some of the clearest, most seamless-looking global views of the icy moon's surface produced so far. The views were created using 13 years of data acquired by the Visual and Infrared Mapping Spectrometer (VIMS) instrument on board NASA's Cassini spacecraft. The images are the result of a focused effort to smoothly combine data fr om the multitude of different observations VIMS made under a wide variety of lighting and viewing conditions over the course of Cassini's mission.
Спойлер
Previous VIMS maps of Titan (for example, PIA02145) display great variation in imaging resolution and lighting conditions, resulting in obvious seams between different areas of the surface. With the seams now gone, this new collection of images is by far the best representation of how the globe of Titan might appear to the casual observer if it weren't for the moon's hazy atmosphere, and it likely will not be superseded for some time to come.

Observing the surface of Titan in the visible region of the spectrum is difficult, due to the globe-enshrouding haze around the moon. This is primarily because small particles called aerosols in Titan's upper atmosphere strongly scatter visible light. But Titan's surface can be more readily imaged in a few infrared "windows" -- infrared wavelengths where scattering and absorption of light is much weaker. This is wh ere the VIMS instrument excelled, parting the haze to obtain clear images of Titan's surface. (For comparison, Figure B shows Titan as it appears in visible light, as does PIA11603.)

Making mosaics of VIMS images of Titan has always been a challenge because the data were obtained over many different flybys with different observing geometries and atmospheric conditions. One result is that very prominent seams appear in the mosaics that are quite difficult for imaging scientists to remove. But, through laborious and detailed analyses of the data, along with time consuming hand processing of the mosaics, the seams have been mostly removed. This is an upd ate to the work previously discussed in PIA20022.

Any full color image is comprised of three color channels: red, green and blue. Each of the three color channels combined to create these views was produced using a ratio between the brightness of Titan's surface at two different wavelengths (1.59/1.27 microns , 2.03/1.27 microns  and 1.27/1.08 microns  ). This technique (called a "band-ratio" technique) reduces the prominence of seams, as well as emphasizing subtle spectral variations in the materials on Titan's surface. For example, the moon's equatorial dune fields appear a consistent brown color here. There are also bluish and purplish areas that may have different compositions from the other bright areas, and may be enriched in water ice.

For a map of Titan with latitudes, longitudes and labeled surface features, see PIA20713.

It is quite clear from this unique se t of images that Titan has a complex surface, sporting myriad geologic features and compositional units. The VIMS instrument has paved the way for future infrared instruments that could image Titan at much higher resolution, revealing features that were not detectable by any of Cassini's instruments.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA'S Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The VIMS team is based at the University of Arizona in Tucson.
...

Credit

NASA/JPL-Caltech/Stéphane Le Mouélic, University of Nantes, Virginia Pasek, University of Arizona

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tnt22

https://saturn.jpl.nasa.gov/resources/7848/group-portrait/
ЦитироватьGroup Portrait



Photojournal: PIA12797

July 30, 2018

On July 29, 2011, Cassini captured five of Saturn's moons in a single frame with its narrow-angle camera. This is a full-color look at a view that was originally published in September 2011 (see PIA14573).

Moons visible in this view: Janus (111 miles, or 179 kilometers across) is on the far left; Pandora (50 miles, or 81 kilometers across) orbits just beyond the thin F ring near the center of the image; brightly reflective Enceladus (313 miles, or 504 kilometers across) appears above center; Saturn's second largest moon, Rhea (949 miles, or 1,528 kilometers across), is bisected by the right edge of the image; and the smaller moon Mimas (246 miles, or 396 kilometers across) is seen just to the left of Rhea.

This view looks toward the northern, sunlit side of the rings from just above the ringplane. Rhea is closest to Cassini here. The rings are beyond Rhea and Mimas. Enceladus is beyond the rings. The view was acquired at a distance of approximately 684,000 miles (1.1 million kilometers) from Rhea and 1.1 million miles (1.8 million kilometers) from Enceladus.
Спойлер
The Cassini spacecraft ended its mission on Sept. 15, 2017.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Credit

NASA/JPL-Caltech/Space Science Institute

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https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA14943
ЦитироватьAUGUST 13, 2018

Translucent Arcs



Saturn's rings are perhaps the most recognized feature of any world in our solar system. Cassini spent more than a decade examining them more closely than any spacecraft before it.

The rings are made mostly of particles of water ice that range in size from smaller than a grain of sand to as large as mountains. The ring system extends up to 175,000 miles (282,000 kilometers) from the planet, but for all their immense width, the rings are razor-thin, about 30 feet (10 meters) thick in most places.

From the right angle you can see straight through the rings, as in this natural-color view that looks from south to north. Cassini obtained the images that comprise this mosaic on April 25, 2007, at a distance of approximately 450,000 miles (725,000 kilometers) from Saturn.
Спойлер
The Cassini spacecraft ended its mission on Sept. 15, 2017.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.
ЦитироватьImage Details

Mission: Cassini-Huygens

Target: Saturn

Spacecraft: Cassini Orbiter

Instrument: Imaging Science Subsystem - Narrow Angle

Full-Res TIFF: PIA14943.tif

Full-Res JPG: PIA14943.jpg

Image credit: NASA/JPL-Caltech/Space Science Institute
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tnt22

https://saturn.jpl.nasa.gov/resources/7850/tete-a-tete/
ЦитироватьTête-à-tête



Photojournal: PIA22648

August 20, 2018

Saturn's moon Tethys disappears behind Titan as observed by Cassini on Nov. 26, 2009. Tethys is about 660 miles (1,070 kilometers) across. At about 3,200 miles (5,100 kilometers) wide, Titan is larger than the planet Mercury, and was much closer to Cassini than Tethys at the time of this image. Titan is planet-like in another way: it's wrapped in a thick atmosphere, which can be clearly seen here where it overlaps icy Tethys in the distance beyond.

Cassini captured this natural-color image at a distance of approximately 620,000 miles (1 million kilometers) from Titan.
Спойлер
The Cassini spacecraft ended its mission on Sept. 15, 2017.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and https://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.

Credit

NASA/JPL-Caltech/Space Science Institute

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https://saturn.jpl.nasa.gov/news/3153/saturns-famous-hexagon-may-tower-above-the-clouds/
ЦитироватьSeptember 5, 2018

Saturn's Famous Hexagon May Tower Above the Clouds


Saturn's northern polar hexagon in motion. Credit: NASA/JPL-Caltech/SSI/Hampton University

A new long-term study using data fr om NASA's Cassini spacecraft has revealed a surprising feature emerging at Saturn's northern pole as it nears summertime: a warming, high-altitude vortex with a hexagonal shape, akin to the famous hexagon seen deeper down in Saturn's clouds.

The finding, published Sept. 3 in Nature Communications, is intriguing, because it suggests that the lower-altitude hexagon may influence what happens above, and that it could be a towering structure hundreds of miles in height.
Спойлер
When Cassini arrived at the Saturnian system in 2004, the southern hemisphere was enjoying summertime, while the northern was in the midst of winter. The spacecraft spied a broad, warm high-altitude vortex at Saturn's southern pole but none at the planet's northern pole. The new study reports the first glimpses of a northern polar vortex forming high in the atmosphere, as Saturn's northern hemisphere approached summertime. This warm vortex sits hundreds of miles above the clouds, in the stratosphere, and reveals an unexpected surprise.

"The edges of this newly-found vortex appear to be hexagonal, precisely matching a famous and bizarre hexagonal cloud pattern we see deeper down in Saturn's atmosphere," said Leigh Fletcher of the University of Leicester, lead author of the new study.

Saturn's cloud levels host the majority of the planet's weather, including the pre-existing north polar hexagon. This feature was discovered by NASA's Voyager spacecraft in the 1980s and has been studied for decades; a long-lasting wave potentially tied to Saturn's rotation, it is a type of phenomenon also seen on Earth, as in the Polar Jet Stream.

Its properties were revealed in detail by Cassini, which observed the feature in multiple wavelengths -- from the ultraviolet to the infrared -- using instruments including its Composite Infrared Spectrometer (CIRS). However, at the start of the mission this instrument could not peer farther up into the northern stratosphere, wh ere temperatures were too cold for reliable CIRS infrared observations, leaving these higher-altitude regions relatively unexplored for many years.

"The mystery and extent of the hexagon continue to grow, even after Cassini's 13 years in orbit around Saturn," said Linda Spilker, Cassini project scientist. "I look forward to seeing other new discoveries that remain to be found in the Cassini data."

For more on the new study, visit the European Space Agency's story here:

http://sci.esa.int/cassini-huygens/60589-saturn-s-famous-hexagon-may-tower-above-the-clouds/

Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, California
818-393-6215
Email: Gretchen.p.mccartney@jpl.nasa.gov

Nicolas Altobelli
ESA Cassini-Huygens Project Scientist
European Space Agency
Phone: +34 91 813 1201
Email: nicolas.altobelliesa.int
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tnt22

https://solarsystem.nasa.gov/news/536/cassinis-final-view-of-titans-northern-lakes-and-seas/
ЦитироватьSeptember 13, 2018
Cassini's Final View of Titan's Northern Lakes and Seas


During NASA's Cassini mission's final distant encounter with Saturn's giant moon Titan, the spacecraft captured this view of the enigmatic moon's north polar landscape of lakes and seas, which are filled with liquid methane and ethane. Credit: NASA/JPL-Caltech/SSI

During NASA's Cassini mission's final distant encounter with Saturn's giant moon Titan, the spacecraft captured the enigmatic moon's north polar landscape of lakes and seas, which are filled with liquid methane and ethane.

They were captured on Sept. 11, 2017. Four days later, Cassini was deliberately plunged into the atmosphere of Saturn.

Punga Mare (240 miles, or 390 kilometers, across) is seen just above the center of the mosaic, with Ligeia Mare (300 miles, or 500 kilometers, wide) below center and the vast Kraken Mare stretching off 730 miles (1,200 kilometers) to the left of the mosaic. Titan's numerous smaller lakes can be seen around the seas and scattered around the right side of the mosaic. Among the ongoing mysteries about Titan is how these lakes are formed.

Another mystery at Titan has been the weather. With its dense atmosphere, Titan has a methane cycle much like Earth's water cycle of evaporation, cloud formation, rainfall, surface runoff into rivers, and collection in lakes and seas. During Titan's southern summer, Cassini observed cloud activity over the south pole (see PIA 06112 and PIA06109).

However, typical of observations taken during northern spring and summer, the view here reveals only a few small clouds. They appear as bright features just below the center of the mosaic, including a few above Ligeia Mare.
Спойлер
"We expected more symmetry between the southern and northern summer," said Elizabeth ("Zibi" ;)  Turtle of the Johns Hopkins Applied Physics Lab and the Cassini Imaging Science Subsystem (ISS) team that captured the image. "In fact, atmospheric models predicted summer clouds over the northern latitudes several years ago. So, the fact that they still hadn't appeared before the end of the mission is telling us something interesting about Titan's methane cycle and weather."

"Titan is a fascinating place that really teases us with some of its mysteries," said Turtle.

The images in this mosaic were taken with the ISS narrow-angle camera, using a spectral filter sensitive to wavelengths of near-infrared light centered at 938 nanometers.

The view was obtained at a distance of approximately 87,000 miles (140,000 kilometers) from Titan. Image scale is about 0.5 miles (800 meters) per pixel. The image is an orthographic projection centered on 67.19 degrees north latitude, 212.67 degrees west longitude. An orthographic view is most like the view seen by a distant observer looking through a telescope.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the U.S., England, France and Germany. The imaging operations center and team leader are based at the Space Science Institute in Boulder, Colorado.

News Media Contact

Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-6215
Gretchen.p.McCartney@jpl.nasa.gov

Dwayne Brown / JoAnna Wendel
NASA Headquarters, Washington
202-358-1726 / 202-358-1003
dwayne.c.brown@nasa.gov / joanna.r.wendel@nasa.gov

Page Updated: September 13, 2018
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https://www.nasa.gov/feature/jpl/groundbreaking-science-emerges-from-ultra-close-orbits-of-saturn
ЦитироватьOct. 4, 2018

Groundbreaking Science Emerges fr om Ultra-Close Orbits of Saturn


Illustration: NASA's Cassini spacecraft in orbit around Saturn.
Credits: NASA/JPL-Caltech
Full image and caption

New research emerging fr om the final orbits of NASA's Cassini spacecraft represents a huge leap forward in our understanding of the Saturn system -- especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised.

Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings fr om Cassini's Grand Finale. That's when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.

Knowing Cassini's days were numbered, its mission team went for gold. The spacecraft flew wh ere it was never designed to fly. For the first time, it probed Saturn's magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the flight path push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.
Спойлер

Illustration: NASA's Cassini spacecraft dives between Saturn and its innermost rings, as part of the mission's Grand Finale.
Credits: NASA/JPL-Caltech
Full image and caption

Many more Grand Finale science results are to come, but here are some of today's highlights:
    [/li]
  • Complex organic compounds embedded in water nanograins rain down from Saturn's rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of the organics is different from that found on moon Enceladus -- and also different from that on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.
  • For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes -- a phenomenon known as "ring rain." But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it's all falling out of the rings faster than scientists thought -- as much as 22,000 pounds (10,000 kilograms) of material per second.
  • Scientists were surprised to see what the material looks like in the gap between the rings and Saturn's atmosphere. They knew that the particles throughout the rings ranged from large to small. But the sampling in the gap showed mostly tiny, nanometer-sized particles, like smoke, suggesting that some yet-unknown process is grinding up particles.
  • Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric-current system that connects the rings to the top of Saturn's atmosphere.
  • Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn't block the belt from forming.
  • Unlike every other planet with a magnetic field in our Solar System, Saturn's magnetic field is almost completely aligned with its spin axis. The new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth's magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It's a mystery that physicists will be working to solve.
  • Cassini flew above Saturn's magnetic poles, directly sampling regions wh ere radio emissions are generated. The findings more than doubled the number of direct measurements of radio sources from the planet, one of the few non-terrestrial locations wh ere scientists have been able to study a radio-generation mechanism that is believed to operate throughout the universe.
For the Cassini mission, the science rolling out from Grand Finale orbits more than justifies the calculated risk of diving into the gap -- skimming the upper atmosphere and skirting the edge of the inner rings, said Cassini Project Scientist Linda Spilker.

"Almost everything going on in that region turned out to be a surprise," Spilker said. "That was the importance of going there, to explore a place we'd never been before. And the expedition really paid off -- the data is tremendously exciting."

Analysis of Cassini data from the spacecraft's instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.


A few of the findings from Cassini's direct sampling: complex organics rain down from Saturn's rings; inner-ring particles take on electric charges and travel along magnetic-field lines; newly revealed electric-current system and radiation belt; and up-close measurement of Saturn's near-zero magnetic-field tilt.
Credits: NASA/JPL-Caltech

"Many mysteries remain, as we put together pieces of the puzzle," Spilker said. "Results from Cassini's final orbits turned out to be more interesting than we could have imagined."  

The papers published in Science are:
On Oct. 4, as the Science publication embargo lifts, articles describing research complementary to these findings will post online in Geophysical Research Letters (GRL), a journal of the American Geophysical Union (AGU).


This illustration imagines the view from NASA's Cassini spacecraft during one of its final dives between Saturn and its innermost rings, as part of the mission's Grand Finale.
Credits: NASA/JPL-Caltech
Full image and caption

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.

Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif. 
818-393-6215 
gretchen.p.mccartney@jpl.nasa.gov
 

Dwayne Brown / JoAnna Wendel 
NASA Headquarters, Washington 
202-358-1726 / 202-358-1003 
dwayne.c.brown@nasa.gov / joanna.r.wendel@nasa.gov
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2018-230

Last Updated: Oct. 4, 2018
Editor: Tony Greicius

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ЦитироватьSaturn's Rings Are Disappearing

NASA Goddard

Опубликовано: 17 дек. 2018 г.

Scientists from NASA Goddard have discovered that not only are Saturn's rings younger than previously thought, but also that the rings are actually disappearing at a rapid pace through a process called "ring rain." Learn more about this phenomena in this animated video.
https://www.youtube.com/watch?v=mN8o90UbpmEhttps://www.youtube.com/watch?v=mN8o90UbpmE (1:44)

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https://www.nasa.gov/press-release/goddard/2018/ring-rain
ЦитироватьDec. 17, 2018
RELEASE 18-22

NASA Research Reveals Saturn is Losing Its Rings at "Worst-Case-Scenario" Rate

New NASA research confirms that Saturn is losing its iconic rings at the maximum rate estimated fr om Voyager 1 & 2 observations made decades ago. The rings are being pulled into Saturn by gravity as a dusty rain of ice particles under the influence of Saturn's magnetic field.
Спойлер
https://www.youtube.com/watch?v=mN8o90UbpmE
This video explores how Saturn is losing its rings at a rapid rate in geologic timescales and what that reveals about the planet's history.
Credits: NASA's Goddard Space Flight Center/David Ladd
Download this video

"We estimate that this 'ring rain' drains an amount of water products that could fill an Olympic-sized swimming pool fr om Saturn's rings in half an hour," said James O'Donoghue of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Fr om this alone, the entire ring system will be gone in 300 million years, but add to this the Cassini-spacecraft measured ring-material detected falling into Saturn's equator, and the rings have less than 100 million years to live. This is relatively short, compared to Saturn's age of over 4 billion years." O'Donoghue is lead author of a study on Saturn's ring rain appearing in Icarus December 17.


This image was made as the Cassini spacecraft scanned across Saturn and its rings on April 25, 2016, capturing three sets of red, green and blue images to cover this entire scene showing the planet and the main rings. The images were obtained using Cassini's wide-angle camera at a distance of approximately 1.9 million miles (3 million kilometers) from Saturn and at an elevation of about 30 degrees above the ring plane.
Credits: NASA/JPL-Caltech/Space Science Institute
Full caption

Scientists have long wondered if Saturn was formed with the rings or if the planet acquired them later in life. The new research favors the latter scenario, indicating that they are unlikely to be older than 100 million years, as it would take that long for the C-ring to become what it is today assuming it was once as dense as the B-ring. "We are lucky to be around to see Saturn's ring system, which appears to be in the middle of its lifetime. However, if rings are temporary, perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus and Neptune, which have only thin ringlets today!" O'Donoghue added.

Various theories have been proposed for the ring's origin. If the planet got them later in life, the rings could have formed when small, icy moons in orbit around Saturn collided, perhaps because their orbits were perturbed by a gravitational tug from a passing asteroid or comet.


An artist's impression of how Saturn may look in the next hundred million years. The innermost rings disappear as they rain onto the planet first, very slowly followed by the outer rings.
Credits: NASA/Cassini/James O'Donoghue

The first hints that ring rain existed came from Voyager observations of seemingly unrelated phenomena: peculiar variations in Saturn's electrically charged upper atmosphere (ionosphere), density variations in Saturn's rings, and a trio of narrow dark bands encircling the planet at northern mid-latitudes. These dark bands appeared in images of Saturn's hazy upper atmosphere (stratosphere) made by NASA's Voyager 2 mission in 1981.

In 1986, Jack Connerney of NASA Goddard published a paper in Geophysical Research Letters that linked those narrow dark bands to the shape of Saturn's enormous magnetic field, proposing that electrically charged ice particles from Saturn's rings were flowing down invisible magnetic field lines, dumping water in Saturn's upper atmosphere wh ere these lines emerged from the planet. The influx of water from the rings, appearing at specific latitudes, washed away the stratospheric haze, making it appear dark in reflected light, producing the narrow dark bands captured in the Voyager images.

Saturn's rings are mostly chunks of water ice ranging in size from microscopic dust grains to boulders several yards (meters) across. Ring particles are caught in a balancing act between the pull of Saturn's gravity, which wants to draw them back into the planet, and their orbital velocity, which wants to fling them outward into space. Tiny particles can get electrically charged by ultraviolet light from the Sun or by plasma clouds emanating from micrometeoroid bombardment of the rings. When this happens, the particles can feel the pull of Saturn's magnetic field, which curves inward toward the planet at Saturn's rings. In some parts of the rings, once charged, the balance of forces on these tiny particles changes dramatically, and Saturn's gravity pulls them in along the magnetic field lines into the upper atmosphere.

Once there, the icy ring particles vaporize and the water can react chemically with Saturn's ionosphere. One outcome from these reactions is an increase in the lifespan of electrically charged particles called H3+ ions, which are made up of three protons and two electrons. When energized by sunlight, the H3+ ions glow in infrared light, which was observed by O'Donoghue's team using special instruments attached to the Keck telescope in Mauna Kea, Hawaii.

Their observations revealed glowing bands in Saturn's northern and southern hemispheres wh ere the magnetic field lines that intersect the ring plane enter the planet. They analyzed the light to determine the amount of rain from the ring and its effects on Saturn's ionosphere. They found that the amount of rain matches remarkably well with the astonishingly high values derived more than three decades earlier by Connerney and colleagues, with one region in the south receiving most of it.

The team also discovered a glowing band at a higher latitude in the southern hemisphere. This is wh ere Saturn's magnetic field intersects the orbit of Enceladus, a geologically active moon that is shooting geysers of water ice into space, indicating that some of those particles are raining onto Saturn as well. "That wasn't a complete surprise," said Connerney. "We identified Enceladus and the E-ring as a copious source of water as well, based on another narrow dark band in that old Voyager image." The geysers, first observed by Cassini instruments in 2005, are thought to be coming from an ocean of liquid water beneath the frozen surface of the tiny moon. Its geologic activity and water ocean make Enceladus one of the most promising places to search for extraterrestrial life.


Saturn's moon Enceladus drifts before the rings and the tiny moon Pandora in this view that NASA's Cassini spacecraft captured on Nov. 1, 2009. The entire scene is backlit by the Sun, providing striking illumination for the icy particles that make up both the rings and the jets emanating from the south pole of Enceladus, which is about 314 miles (505 km) across. Pandora, which is about (52 miles, 84 kilometers) wide, was on the opposite side of the rings from Cassini and Enceladus when the image was taken. This view looks toward the night side on Pandora as well, which is lit by dim golden light reflected from Saturn.
Credits: NASA/JPL-Caltech/Space Science Institute
Full caption

The team would like to see how the ring rain changes with the seasons on Saturn. As the planet progresses in its 29.4-year orbit, the rings are exposed to the Sun to varying degrees. Since ultraviolet light from the Sun charges the ice grains and makes them respond to Saturn's magnetic field, varying exposure to sunlight should change the quantity of ring rain.

The research was funded by NASA and the NASA Postdoctoral Program at NASA Goddard, administered by the Universities Space Research Association. The W.M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and the data in the form of its files are available from the Keck archive. The authors wish to recognize the significant cultural role and reverence that the summit of Mauna Kea has within the indigenous Hawaiian community; they are fortunate to have the opportunity to conduct observations from this mountain.

Bill Steigerwald / Nancy Jones

NASA Goddard Space Flight Center, Greenbelt, Maryland

301-286-8955 / 301-286-0039

william.a.steigerwald@nasa.gov / nancy.n.jones@nasa.gov
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Last Updated: Dec. 19, 2018
Editor: Bill Steigerwald

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https://ria.ru/20181218/1548208816.html
ЦитироватьВ НАСА выяснили, когда исчезнут кольца Сатурна
18 декабря, 17:31

МОСКВА, 18 дек - РИА Новости. Ученые НАСА выяснили, что кольца Сатурна могут исчезнуть менее чем через 100 миллионов лет, сообщает интернет-портал Phys.org со ссылкой на исследование космического агентства.

Результаты исследования были опубликованы в научном издании Icarus в понедельник. Оценки ученых основаны на данных, собранных зондами "Вояджер" и "Кассини".
Спойлер
Как отмечается, под действием гравитации частицы льда, из которого преимущественно состоят кольца, притягиваются к планете, что вызывает их стремительное истощение.

"По нашим оценкам, так называемый дождь, который выпадает из колец Сатурна в виде продуктов воды, мог бы за полчаса наполнить олимпийский бассейн", - цитирует портал одного из авторов исследования Джеймса О'Донохью. По его словам, один этот факт уже указывает на то, что "вся система колец исчезнет через 300 миллионов лет". Однако если учитывать данные аппарата "Кассини" о количестве материала, который выпадает на экватор планеты, "кольца просуществуют меньше 100 миллионов лет".

"Это довольно небольшой срок, принимая во внимание, что возраст Сатурна составляет более четырех миллиардов лет", - отметил О'Донохью.

Ученые давно пытались выяснить происхождение и возраст колец Сатурна. По одной версии, они сформировались вместе с планетой, по другой - образовались гораздо позднее. Результаты исследования показали, что возраст колец вряд ли составляет более 100 миллионов лет. В этом случае они могли сформироваться из-за столкновения небольших ледяных спутников на орбите планеты.

"Нам повезло, что мы можем увидеть систему колец Сатурна, которая, по всей вероятности, находится в середине своего жизненного пути", - заявил ученый. Он также отметил, что мы могли не застать те времена, когда у Юпитера, Урана и Нептуна были крупные системы колец, которые к сегодняшнему дню, вероятно, значительно истощились.
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https://ria.ru/20190117/1549513335.html
ЦитироватьАстрономы узнали, когда Сатурн стал "властелином колец"
17 янв, 22:00

МОСКВА, 17 янв – РИА Новости. Героическая гибель зонда "Кассини" помогла планетологам точно взвесить кольца Сатурна и выяснить, что они появились относительно недавно, не более 100 миллионов лет назад. Их выводы были представлены в журнале Science.
Цитировать"Никто не доверял прошлым замерам массы колец, полученным в ходе наблюдений за волнами на их поверхности. Дело в том, что внутри них могут присутствовать крупные частицы, которые не будут колебаться подобным образом. Поэтому мы всегда подозревали, что они могут быть на самом деле намного тяжелее", — рассказывает Буркхард Милитцер (Burkhard Militzer) из университета Калифорнии в Беркли (США).
Спойлер
Сатурнианские кольца были открыты Галилео Галилеем в 1610 году, который посчитал их тремя крупными спутниками. В середине XVII века Христиан Гюйгенс выяснил, что "спутники" Галилея на самом деле являются кольцами, состоящими из мельчайших частичек пыли и льда.

О природе этих колец ученые спорят до сих пор. Часть планетологов полагает, что они возникли из осколков древней протопланеты на заре юности Солнечной системы, тогда как другие считают их продуктом недавних катаклизмов.

Споров добавляет и то, что зонд "Кассини" обнаружил, что Сатурн "высасывает" воду из своих колец с очень высокой скоростью. Как недавно выяснили в НАСА, ближайшие к планете кольца исчезнут в самое ближайшее время по космическим меркам, а вся их система будет съедена Сатурном примерно через 300 миллионов лет.

Подобные открытия укрепили позиции сторонников теории "молодых колец" и заставили планетологов задуматься о том, когда они появились. Точный ответ на этот вопрос, как объясняет Милитцер, можно получить, зная всего два параметра – массу пыли и частичек льда внутри них и то, насколько хорошо кольца отражают свет Солнца.

Дело в том, что кольца Сатурна и других планет-гигантов должны постепенно тускнеть из-за того, что на поверхности их зерен льда должны осаждаться миниатюрные частицы пыли и органика, постепенно темнеющая в результате ее "бомбардировки" ультрафиолетовыми лучами Солнца.
Соответственно, чем светлее кольца, тем меньше их возраст, и наоборот. Скорость потускнения, в свою очередь, зависит от их массы, толщины и состава – чем больше материи скрывается внутри них, тем медленнее будут "чернеть" эти структуры.

"Кассини" измерил яркость колец Сатурна в первые же годы своей работы на его орбите. С другой стороны, их точная масса оставалась недоступной для него до самого конца жизни по той причине, что зонд не сближался с ними на достаточно тесное расстояние для того, чтобы отделить их гравитационное влияние от притяжения планеты.

Первая такая возможность появилась у "Кассини" в 2017 году, когда зонд начал совершать "нырки" через кольца, готовясь к героической гибели в атмосфере Сатурна. Эти пролеты помогли Милитцеру и его коллегам измерить структуру гравитационного поля планеты и приступить к замерам массы колец.

Японские и французские планетологи пришли к выводу, что знаменитые кольца Сатурна представляют собой раздробленные осколки "зародыша" планеты, который планета-гигант "съела" во время путешествия к центру Солнечной системы в первые мгновения ее существования.

"Когда я впервые увидел эти данные, я не поверил глазам, так как они полностью противоречили нашим моделям. Прошло немало времени, прежде чем мы признали, что там есть что-то еще, что меняло гравитационные поля непредсказуемым образом. Оказалось, что в атмосфере Сатурна бушуют гигантские потоки воздуха, проникающие на 9000 километров внутрь планеты", — продолжает планетолог.

Когда ученые учли эту аномалию, они обнаружили, что масса колец была неожиданно небольшой – она составляла около 15 миллионов миллиардов тонн. Это примерно равно половине массы Мимаса, одной из самых маленьких лун Сатурна, похожей на "звезду смерти", и сопоставимо с весом небольших астероидов.

Это, в свою очередь, означает, что Сатурн стал "властелином колец" совсем недавно, примерно 100 миллионов лет назад. Его прародителем могла выступать как и небольшая луна, так и крупная комета, что хорошо сочетается с тем, что "Кассини" обнаружил массу органики внутри колец в последние секунды своей жизни.
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https://solarsystem.nasa.gov/news/904/cassini-reveals-surprises-with-titans-lakes/
ЦитироватьApril 15, 2019
Cassini Reveals Surprises with Titan's Lakes


This near-infrared, color view from Cassini shows the sun glinting off of Titan's north polar seas. Credit: NASA/JPL-Caltech/Univ. Arizona/Univ. Idaho | › Full Image and Caption

On its final flyby of Saturn's largest moon in 2017, NASA's Cassini spacecraft gathered radar data revealing that the small liquid lakes in Titan's northern hemisphere are surprisingly deep, perched atop hills and filled with methane.

The new findings, published April 15 in Nature Astronomy, are the first confirmation of just how deep some of Titan's lakes are (more than 300 feet, or 100 meters) and of their composition. They provide new information about the way liquid methane rains on, evaporates from and seeps into Titan — the only planetary body in our solar system other than Earth known to have stable liquid on its surface.
Спойлер
Scientists have known that Titan's hydrologic cycle works similarly to Earth's — with one major difference. Instead of water evaporating from seas, forming clouds and rain, Titan does it all with methane and ethane. We tend to think of these hydrocarbons as a gas on Earth, unless they're pressurized in a tank. But Titan is so cold that they behave as liquids, like gasoline at room temperature on our planet.

Scientists have known that the much larger northern seas are filled with methane, but finding the smaller northern lakes filled mostly with methane was a surprise. Previously, Cassini data measured Ontario Lacus, the only major lake in Titan's southern hemisphere. There they found a roughly equal mix of methane and ethane. Ethane is slightly heavier than methane, with more carbon and hydrogen atoms in its makeup.
ЦитироватьThis was Cassini's last hurrah at Titan, and it really was a feat.

- Jonathan Lunine, Cassini Scientist
"Every time we make discoveries on Titan, Titan becomes more and more mysterious," said lead author Marco Mastrogiuseppe, Cassini radar scientist at Caltech in Pasadena, California. "But these new measurements help give an answer to a few key questions. We can actually now better understand the hydrology of Titan."

Adding to the oddities of Titan, with its Earth-like features carved by exotic materials, is the fact that the hydrology on one side of the northern hemisphere is completely different than the that of other side, said Cassini scientist and co-author Jonathan Lunine of Cornell University in Ithaca, New York.

"It is as if you looked down on the Earth's North Pole and could see that North America had completely different geologic setting for bodies of liquid than Asia does," Lunine said.

On the eastern side of Titan, there are big seas with low elevation, canyons and islands. On the western side: small lakes. And the new measurements show the lakes perched atop big hills and plateaus. The new radar measurements confirm earlier findings that the lakes are far above sea level, but they conjure a new image of landforms — like mesas or buttes — sticking hundreds of feet above the surrounding landscape, with deep liquid lakes on top.

The fact that these western lakes are small — just tens of miles across — but very deep also tells scientists something new about their geology: It's the best evidence yet that they likely formed when the surrounding bedrock of ice and solid organics chemically dissolved and collapsed. On Earth, similar water lakes are known as karstic lakes. Occurring in in areas like Germany, Croatia and the United States, they form when water dissolves limestone bedrock.

Alongside the investigation of deep lakes, a second paper in Nature Astronomy helps unravel more of the mystery of Titan's hydrologic cycle. Researchers used Cassini data to reveal what they call transient lakes. Different sets of observations — from radar and infrared data — seem to show liquid levels significantly changed.

The best explanation is that there was some seasonally driven change in the surface liquids, said lead author Shannon MacKenzie, planetary scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. "One possibility is that these transient features could have been shallower bodies of liquid that over the course of the season evaporated and infiltrated into the subsurface," she said.

These results and the findings from the Nature Astronomy paper on Titan's deep lakes support the idea that hydrocarbon rain feeds the lakes, which then can evaporate back into the atmosphere or drain into the subsurface, leaving reservoirs of liquid stored below

Cassini, which arrived in the Saturn system in 2004 and ended its mission in 2017 by deliberately plunging into Saturn's atmosphere, mapped more than 620,000 square miles (1.6 million square kilometers) of liquid lakes and seas on Titan's surface. It did the work with the radar instrument, which sent out radio waves and collected a return signal (or echo) that provided information about the terrain and the liquid bodies' depth and composition, along with two imaging systems that could penetrate the moon's thick atmospheric haze.

The crucial data for the new research were gathered on Cassini's final close flyby of Titan, on April 22, 2017. It was the mission's last look at the moon's smaller lakes, and the team made the most of it. Collecting echoes from the surfaces of small lakes while Cassini zipped by Titan was a unique challenge.

"This was Cassini's last hurrah at Titan, and it really was a feat," Lunine said

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.
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https://tass.ru/kosmos/6342334
Цитировать17 АПР, 08:18
На спутнике Сатурна могут существовать испаряющиеся озера из жидкого метана

Планетологи допускают наличие на поверхности Титана сезонных изменений

НЬЮ-ЙОРК, 17 апреля. /ТАСС/. Пересыхающие озера из жидкого метана, возможно, существуют на поверхности спутника Сатурна - Титана. Об этом сообщил во вторник портал Space.com со ссылкой на результаты двух исследований, в которых обобщались наблюдения, сделанные во время исследования Сатурна автоматической станцией Cassini. Она пролетала мимо Титана более 100 раз и на некоторых снимках планетологи рассмотрели три озера, наполненные жидкостью, которые впоследствии исчезли. Планетологи назвали их "призрачными озерами" и предположили, что на поверхности Титана происходят сезонные изменения.

Во времени последнего прохождения над поверхностью Титана в апреле 2017 года станция проводила замеры с помощью альтиметра и, в частности, определила глубину впадин, в которых скапливается жидкость. Оказалось, что они имеют глубину до 100 метров, и в них скапливается жидкий метан.

"Титан - единственное небесное тело, помимо Земли, на поверхности которого наблюдается жидкость, - отметила планетолог из Лаборатории реактивного движения в Пасадине (штат Калифорния) Розали Лопес. - Некоторые из нас называют Титан "Землей дальнего космоса".
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Автоматическая межпланетная станция Cassini - совместный проект NASA, а также Европейского и Итальянского космических агентств. Она была запущена в октябре 1997 года с целью исследований Сатурна, его колец и спутников. С момента запуска Cassini преодолела 7,9 млрд километров, совершила 294 оборота вокруг Сатурна, 162 раза сближалась с его спутниками и открыла шесть новых. В сентябре 2017 года станция вошла в плотные слои атмосферы Сатурна и прекратила свое существование.

Сатурн - газовый гигант, шестая планета Солнечной системы и вторая по размерам после Юпитера. Вокруг планеты обращается 62 известных науке спутника и четыре кольца - три основных и четвертое более тонкое.

Титан - самый крупный из спутников Сатурна, открытый в 1655 году голландским астрономом Христианом Гюйгенсом. Его диаметр - 5152 километра, он на 50% больше естественного спутника земли - Луны и на 80% массивнее ее. Это единственный спутник в Солнечной системе, имеющий плотную атмосферу, состоящую, в основном, из азота, метана и этана.
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Кассини умер, но дело его живёт:
Среди метановых озер на Титане нашлись тысячелетние водоемы глубиной больше 100 метров
ЦитироватьОзера на спутнике Сатурна, Титане, являются полноценными водоемами с глубиной свыше ста метров и существуют на протяжении по меньшей мере нескольких тысячелетий, выяснили ученые, проанализировав снимки аппарата «Кассини». Помимо стабильных озер на этом небесном теле есть и регулярно пересыхающие «лужи» и неглубокие пруды. Это делает Титан вторым телом в Солнечной системе, где есть не только атмосфера, но и водоемы, а также стабильный круговорот жидкости в системе — правда, метановой.
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Море Лигейи (в честь одной из сирен в древнегреческой мифологии) на Титане, радарное изображениеNASA/JPL-Caltech/ASI/Cornell

Группа астрономов из Италии и США показала, что глубина некоторых озер превышает сто метров, а жидкость в них действительно состоит преимущественно из метана (который хорошо пропускает радиоволны, и потому его можно определить по радарным данным). А другие исследователи, из США и Франции, описали, напротив, сезонное пересыхание озер поменьше, которые скорее можно назвать лужами. Обе группы ученых рассмотрели также вопрос взаимодействия метана с грунтом Титана и пришли к выводу, что жидкий метан играет на этом небесном теле заметную роль в геологических процессах. Метан, как и вода на Земле, растворяет некоторые горные породы, вымывает карстовые полости, впитывается в поверхность и участвует в глобальном круговороте.
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Вообще, исследовать солнечную систему автоматами - это примерно то же самое, что посылать робота вместо себя в фитнес, качаться.Зомби. Просто Зомби (с)
Многоразовость - это бяка (с) Дмитрий Инфан