"Кассини" !

[tnt22]

https://www.nasa.gov/image-feature/jpl/pia21621/haze-on-the-horizon

July 27, 2017
Haze on the Horizon



This false-color view from NASA's Cassini spacecraft gazes toward the rings beyond Saturn's sunlit horizon. Along the limb (the planet's edge) at left can be seen a thin, detached haze. This haze vanishes toward the left side of the scene.

Спойлер

Cassini will pass through Saturn's upper atmosphere during the final five orbits of the mission, before making a fateful plunge into Saturn on Sept. 15, 2017. The region through which the spacecraft will fly on those last orbits is well above the haze seen here, which is in Saturn's stratosphere. In fact, even when Cassini plunges toward Saturn to meet its fate, contact with the spacecraft is expected to be lost before it reaches the depth of this haze.

This view is a false-color composite made using images taken in red, green and ultraviolet spectral filters. The images were obtained using the Cassini spacecraft narrow-angle camera on July 16, 2017, at a distance of about 777,000 miles (1.25 million kilometers) from Saturn. Image scale is about 4 miles (7 kilometers) per pixel on Saturn.

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 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 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 https://ciclops.org.

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

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Last Updated: July 27, 2017
Editor: Tony Greicius

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[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 1 ч. назад

We caught a rare sight: the dancing lights of #Saturn's southern aurora. Learn more: https://go.nasa.gov/2v4udFy

Video

https://saturn.jpl.nasa.gov/resources/7720/

Southern Auroras Over Saturn

Спойлер

Photojournal: PIA21623

[свернуть]

July 28, 2017

Cassini gazed toward high southern latitudes near Saturn's south pole to observe ghostly curtains of dancing light -- Saturn's southern auroras, or southern lights. These natural light displays at the planet's poles are created by charged particles raining down into the upper atmosphere, making gases there glow.

The dark area at the top of this scene is Saturn's night side. The auroras rotate from left to right, curving around the planet as Saturn rotates over about 70 minutes, compressed here into a movie sequence of about five seconds. (You can see more Cassini videos here).

Спойлер

Background stars are seen sliding behind the planet. Cassini was moving around Saturn during the observation, keeping its gaze fixed on a particular spot on the planet, which causes a shift in the distant background over the course of the observation.

Some of the stars seem to make a slight turn to the right just before disappearing. This effect is due to refraction -- the starlight gets bent as it passes through the atmosphere, which acts as a lens.
Random bright specks and streaks appearing from frame to frame are due to charged particles and cosmic rays hitting the camera detector.

For other examples of the auroras seen by Cassini earlier in the mission, see Glowing Southern Lights​ and Northern Aurora in Motion.

The aim of this observation was to observe seasonal changes in the brightness of Saturn's auroras, and to compare with the simultaneous observations made by Cassini's infrared and ultraviolet imaging spectrometers.

The original images in this movie sequence have a size of 256x256 pixels; both the original size and a version enlarged to 500x500 pixels are available here. The small image size is the result of a setting on the camera that allows for shorter exposure times than full-size (1024x1024 pixel) images. This enabled Cassini to take more frames in a short time and still capture enough photons from the auroras for them to be visible.

The images were taken in visible light using the Cassini spacecraft narrow-angle camera on July 20, 2017, at a distance of about 620,000 miles (1 million kilometers) from Saturn. The views look toward 74 degrees south latitude on Saturn. Image scale is about 0.9 mile (1.4 kilometers) per pixel on Saturn.
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 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 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 https://ciclops.org.
 
Credit

NASA/JPL-Caltech/Space Science Institute

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[tnt22]

https://saturn.jpl.nasa.gov/mission/grand-finale/grand-finale-orbit-guide/#Orbit_16

IN PROGRESS: Orbit 286 - July 29 - August 4

[TH]Event[/TH][TH]Date[/TH][TH]Spacecraft Time (UTC)[/TH][TH]Local Time (PDT)[/TH][TH]Notes[/TH]

Apoapse	Jul 29	12:33 a.m.	5:33 p.m. (Jul 28 )
Ring Crossing #16	Aug 1	6:05 a.m.	11:05 p.m. (Jul 31)
Downlink	Aug 1	10:57 p.m.	3:57 p.m.	Estimated Earth Received Time (ERT) is 5:14 p.m. PDT on August 1.

[/li]
• 
  During this orbit, Cassini's Ultraviolet Imaging Spectrograph (UVIS) makes a long observation of Saturn's northern aurora at an unusually close range, producing some of the highest-resolution auroral images of the entire mission.
• 
  Cassini's Visible and Infrared Mapping Spectrometer (VIMS) observes Saturn's aurora during this orbit as well. This observation is the closest and highest-resolution auroral observation VIMS makes during Cassini's entire mission.
• 
  The spacecraft's Composite Infrared Spectrometer (CIRS) observes the south polar region of Saturn's moon Enceladus during this orbit, studying winter temperatures on the moon's surface. This is the instrument's last opportunity of the mission to study the temperatures on Enceladus, to help researchers understand how they change over time.
• 
  During this orbit, Cassini gets within 1,820 miles (2,920 kilometers) of Saturn's 1-bar level. Cassini also passes within 2,980 miles (4,790 kilometers) of the inner edge of Saturn's D ring.
  

[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 1 ч. назад

#SaturnSaturday We've started #GrandFinale orbit #16 of 22. The agenda includes more aurora observations. Details: https://go.nasa.gov/2v5cFZZ 

[tnt22]

A Titan Discovery

NASA Goddard

Опубликовано: 28 июл. 2017 г.

NASA Goddard scientists have made an exciting discovery on Saturn's largest moon, Titan. The team has definitively detected the molecule acrylonitrile in Titan's atmosphere - a finding that has astrobiological relevance.

(1:37)

[tnt22]

https://www.nasa.gov/feature/goddard/2017/nasa-finds-moon-of-saturn-has-chemical-that-could-form-membranes

July 28, 2017

NASA Finds Moon of Saturn Has Chemical That Could Form 'Membranes'

NASA scientists have definitively detected the chemical acrylonitrile in the atmosphere of Saturn's moon Titan, a place that has long intrigued scientists investigating the chemical precursors of life.

Спойлер

On Earth, acrylonitrile, also known as vinyl cyanide, is useful in the manufacture of plastics. Under the harsh conditions of Saturn's largest moon, this chemical is thought to be capable of forming stable, flexible structures similar to cell membranes. Other researchers have previously suggested that acrylonitrile is an ingredient of Titan's atmosphere, but they did not report an unambiguous detection of the chemical in the smorgasbord of organic, or carbon-rich, molecules found there.

Now, NASA researchers have identified the chemical fingerprint of acrylonitrile in Titan data collected by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. The team found large quantities of the chemical on Titan, most likely in the stratosphere — the hazy part of the atmosphere that gives this moon its brownish-orange color.

"We found convincing evidence that acrylonitrile is present in Titan's atmosphere, and we think a significant supply of this raw material reaches the surface," said Maureen Palmer, a researcher with the Goddard Center for Astrobiology at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of a July 28, 2017, paper in Science Advances.


NASA scientists have definitively detected the chemical acrylonitrile, also known as vinyl cyanide, in the atmosphere of Saturn's moon Titan, a place that has long intrigued scientists investigating the chemical precursors of life.
Credits: NASA's Goddard Space Flight Center
Download this video in HD formats fr om NASA Goddard's Scientific Visualization Studio

The cells of Earth's plants and animals would not hold up well on Titan, where surface temperatures average minus 290 degrees Fahrenheit (minus 179 degrees Celsius), and lakes brim with liquid methane.

In 2015, university scientists tackled the question of whether any organic molecules likely to be on Titan could, under such inhospitable conditions, form structures similar to the lipid bilayers of living cells on Earth. Thin and flexible, the lipid bilayer is the main component of the cell membrane, which separates the inside of a cell from the outside world. This team identified acrylonitrile as the best candidate.

Those researchers proposed that acrylonitrile molecules could come together as a sheet of material similar to a cell membrane. The sheet could form a hollow, microscopic sphere that they dubbed an "azotosome." This sphere could serve as a tiny storage and transport container, much like the spheres that lipid bilayers can form.

"The ability to form a stable membrane to separate the internal environment from the external one is important because it provides a means to contain chemicals long enough to allow them to interact," said Michael Mumma, director of the Goddard Center for Astrobiology, which is funded by the NASA Astrobiology Institute. "If membrane-like structures could be formed by vinyl cyanide, it would be an important step on the pathway to life on Saturn's moon Titan."

The Goddard team determined that acrylonitrile is plentiful in Titan's atmosphere, present at concentrations up to 2.8 parts per billion. The chemical is probably most abundant in the stratosphere, at altitudes of at least 125 miles (200 kilometers). Eventually, acrylonitrile makes its way to the cold lower atmosphere, wh ere it condenses and rains out onto the surface.

The researchers calculated how much material could be deposited in Ligeia Mare, Titan's second-largest lake, which occupies roughly the same surface area as Earth's Lake Huron and Lake Michigan together. Over the lifetime of Titan, the team estimated, Ligeia Mare could have accumulated enough acrylonitrile to form about 10 million azotosomes in every milliliter, or quarter-teaspoon, of liquid. That's compared to roughly a million bacteria per milliliter of coastal ocean water on Earth.

The key to detecting Titan's acrylonitrile was to combine 11 high-resolution data sets from ALMA. The team retrieved them from an archive of observations originally intended to calibrate the amount of light being received by the telescope array.

In the combined data set, Palmer and her colleagues identified three spectral lines that match the acrylonitrile fingerprint. This finding comes a decade after other researchers inferred the presence of acrylonitrile from observations made by the mass spectrometer on NASA's Cassini spacecraft.

"The detection of this elusive, astrobiologically relevant chemical is exciting for scientists who are eager to determine if life could develop on icy worlds such as Titan," said Goddard scientist Martin Cordiner, senior author on the paper. "This finding adds an important piece to our understanding of the chemical complexity of the solar system."

ALMA, an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere, the U.S. National Science Foundation and the National Institutes of Natural Sciences of Japan in cooperation with the Republic of Chile.


By Elizabeth Zubritsky
NASA's Goddard Space Flight Center, Greenbelt, Md.

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Last Updated: July 28, 2017
Editor: Rob Garner

[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 37 мин. назад

It's summer in #Saturn's northern hemisphere, bringing continuous sunshine to the planet's far north https://go.nasa.gov/2ucEtXX 

https://saturn.jpl.nasa.gov/resources/7719/

Good Old Summer Time

Спойлер

 
Photojournal: PIA21337

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July 31, 2017

Saturn's northern hemisphere reached its summer solstice in mid-2017, bringing continuous sunshine to the planet's far north.

Спойлер

The solstice took place on May 24, 2017. The Cassini mission is using the unparalleled opportunity to observe changes that occur on the planet as the Saturnian seasons turn.

This view looks toward the sunlit side of the rings from about 17 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on April 17, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers.

The view was acquired at a distance of approximately 733,000 miles (1.2 million kilometers) from Saturn. Image scale is 44 miles (70 kilometers) per pixel.
  
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 http://saturn.jpl.nasa.gov and http://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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[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 8 мин назад

We captured these unprocessed images on Jul. 30. See more raw images: https://go.nasa.gov/2vcfmZR 

Спойлер

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[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 19 ч. назад

We're about to begin ring crossing #16 of 22. See the story of the #GrandFinale phase of our mission at #Saturn https://go.nasa.gov/1Up1oba

[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 1 ч. назад

We've successfully completed the 16th crossing between #Saturn and its rings. The next will take place on Aug. 7. https://go.nasa.gov/2uhIPi3 

[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 10 ч. назад

One Final Burn: our team recently performed the last planned orbit maneuver of the mission - https://go.nasa.gov/2v0xvqU 

https://saturn.jpl.nasa.gov/news/3096/one-final-burn/

One Final Burn

By Jay R. Thompson

August 2, 2017

"It's all good," said Cassini Project Manager Earl Maize after the spacecraft's successful course adjustment July 15, adding, "What a machine." Maize and several other members of Cassini's flight team were in the mission control room at JPL early Saturday morning to check on the spacecraft after its final planned maneuver.

Спойлер

Cassini's flight team haven't ruled out the possibility of another maneuver, but they say it's unlikely.

Since launch, Cassini has used its propulsion system to adjust course 360 times. The adjustments, called orbit trim maneuvers, are performed using either the spacecraft's main engine or the attitude control thrusters. Cassini used its thrusters for the July 15 maneuver, as it has for nearly half of its maneuvers.

The maneuvers, or "burns," are small corrections that nudge Cassini back toward its intended and ideal trajectory (called the "reference trajectory"). Cassini has not performed all of the 492 burns the team planned, because not all of them were needed. When the spacecraft is extremely close to its reference trajectory, it's simply not necessary to start up Cassini's propulsion system for 1 millimeter (0.04 inch) per second of velocity change, or "delta-v."
...

"We don't like to do them when they're below 10 millimeters [0.4 inches] per second," said Julie Webster, Cassini manager of spacecraft operations. According to data that Cassini transmitted to Earth July 15, the final burn lasted 153.125 seconds and gave the spacecraft 143.64 millimeters (5.7 inches) per second of delta-v.

Cassini is now less two months from end of mission. If all goes well for its remaining orbits, the spacecraft's main engine won't be used ever again. The thrusters, however, will be used throughout the mission's remaining weeks, especially during Cassini's plunge into Saturn on Sept. 15 when the thrusters will, for as long as possible, keep the spacecraft oriented so that its radio antenna is pointed at Earth.

Neither Maize nor Webster really needed to be in mission control Saturday morning, but they wanted to. "We're just here because we're nerds, and because it's the last one," Webster said. "I'm also here for moral support...and because Earl brought doughnuts."

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[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 12 мин назад

We're about to begin #GrandFinale orbit #17 of 22. Plans include observations of the "propellers" in Saturn's rings: https://go.nasa.gov/2qcf2Vx 

[tnt22]

https://saturn.jpl.nasa.gov/mission/grand-finale/grand-finale-orbit-guide/#Orbit_17

IN PROGRESS: Orbit 287 - August 4 - August 10

[TH]Event[/TH][TH]Date[/TH][TH]Spacecraft Time (UTC)[/TH][TH]Local Time (PDT)[/TH][TH]Notes[/TH][TH]Apoapse[/TH][TH]Ring Crossing #17[/TH][TH]Downlink[/TH]

Aug 4	11:46 a.m.	4:46 a.m.
Aug 7	5:19 p.m.	10:19 a.m.
Aug 8	3:11 p.m.	8:11 a.m.	Estimated Earth Received Time (ERT) is 9:29 a.m. PDT on August 8.

[/li]
• 
  During this orbit Cassini's Ultraviolet Imaging Spectrograph (UVIS) observes Saturn's northern aurora, attempting to capture the entire auroral oval over several observations.
• 
  The spacecraft's imaging cameras, the Imaging Science Subsystem (ISS), performs the first of two final observations of one of Saturn's tiny, irregular moons, named Kiviuq, which completes about 80 percent of one rotation during Cassini's observation. The observation is intended to improve models of the moon's shape and other of Kiviuq's characteristics.
• 
  The ISS instrument also targets one of Saturn's ring propeller features, and also continues its campaign of observing Saturn's moon Titan for two segments of time, each lasting several hours, to image the moon's atmosphere and surface, in particular to watch Titan's clouds form and change. The spacecraft's Composite Infrared Spectrometer (CIRS) and Visible and Infrared Mapping Spectrometer (VIMS) observe Titan as well.
• 
  Also during this orbit, the spacecraft rolls to calibrate Cassini's magnetometer (MAG).
• 
  During this orbit, Cassini gets within 1,830 miles (2,940 kilometers) of Saturn's 1-bar level. Cassini also passes within 2,960 miles (4,760 kilometers) of the inner edge of Saturn's D ring.
  

[Старый]

Блин, будет жалко когда его грохнут.
Таких первооткрывателей как Кассини и Нью Горизонс наше поколение уже наверно больше не увидит.

[Дмитрий Виницкий]

А посадку на Меркурий?

[pkl]

Старый пишет:
Блин, будет жалко когда его грохнут.    
Таких первооткрывателей как Кассини и Нью Горизонс наше поколение уже наверно больше не увидит.

Это точно. Только сейчас понял, что в 2000-е был золотой век космонавтики!    

Начался с запусков марсианских роверов и закончился пролётом Новых Горизонтов у Плутона. Это было восхитительное время!

Дмитрий Виницкий пишет:
А посадку на Меркурий?    

А её не будет.

[Дмитрий Виницкий]

pkl пишет: 
А её не будет.

Зуб даёте? © 

[pkl]

Нет уж. Если собрать все мои неудавшиеся прогнозы, я бы давно без зубов остался. :{}

[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 28 мин. назад

The thin sliver of #Saturn's moon Prometheus lurks near ghostly structures in Saturn's narrow F ring. Details: https://go.nasa.gov/2vxkkAz 

https://saturn.jpl.nasa.gov/resources/7718/

Prometheus and the Ghostly F Ring

Спойлер

Photojournal: PIA21340

[свернуть]

August 7, 2017

The thin sliver of Saturn's moon Prometheus lurks near ghostly structures in Saturn's narrow F ring in this view from NASA's Cassini spacecraft. Many of the narrow ring's faint and wispy features result from its gravitational interactions with Prometheus (86 kilometers, or 53 miles across).

Спойлер

Most of the small moon's surface is in darkness due to the viewing geometry here. Cassini was positioned behind Saturn and Prometheus with respect to the sun, looking toward the moon's dark side and just a bit of the moon's sunlit northern hemisphere.

Also visible here is a distinct difference in brightness between the outermost section of Saturn's A ring (left of center) and rest of the ring, interior to the Keeler Gap (lower left).

This view looks toward the sunlit side of the rings from about 13 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 13, 2017.

The view was acquired at a distance of approximately 680,000 miles (1.1 million kilometers) from Saturn. Image scale is 4 miles (6 kilometers) per pixel.

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 http://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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[tnt22]

CassiniSaturn‏Подлинная учетная запись @CassiniSaturn 36 мин назад

Happening now: we're about to dive right between #Saturn and the rings. Follow along here: https://go.nasa.gov/2aNCy6t 



24 мин. назад

This is ring crossing #17 of 22. See the complete #GrandFinale orbit guide