Cassini Reveals Saturn’s Hexagon Border


Oh Cassini, have I mentioned lately how much I admire you? In October 2015, https://notestoponder.wordpress.com/2015/10/29/cassinis-curtain-call/ defined you as NASA’s unassuming civil servant, know that your exemplary service to humanity will never be forgotten.

On April 26, 2017 Cassini embarked on the first of 22 dives toward the heart of Saturn. Sliding dutifully between Saturn’s inner ring and outer atmosphere, Cassini encountered little resistance. Unaware of external trepidation, oblivious to collective relief she wasn’t obliterated by cosmic debris, Cassini documented her journey with stoic pride.

On May 4, 2017 NASA released this video, a Cassini eye view exposing mysteries of Saturn’s hexagon north pole cloud system and central vortex. Images that suggest neighboring hexagon and vortex clouds never mix –

In September 2017 a wild abandon death plunge toward Saturn will terminate the mission. Cameras rolling, Cassini’s demise will cement the legacy of an unassuming civil servant determined to advance science.

Outstanding link to Cassini timeline –

https://saturn.jpl.nasa.gov/the-journey/timeline/#saturn-orbit-insertion

Pondering Cassini’s Imminent Demise


April 26, 2017 marks the beginning of NASA’s Cassini Mission end. Twenty years from home, fuel supplies close to exhaustion, Cassini’s imminent demise starts with the first of 22 planned dives between the rings of Saturn. The final plunge on September 22,2017 will lay Cassini to rest somewhere in the arms of Saturn. Mindful of protecting one of Saturn’s 62 moons from impact of an out of control space probe, Cassini’s assisted suicide is planned to maximize scientific discovery.

http://earthsky.org/space/cassini-at-saturn-grand-finale-2017?utm_source=EarthSky+News&utm_campaign=0b882ebc2e-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-0b882ebc2e-393970565&mc_cid=0b882ebc2e&mc_eid=a5b828713b

Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA said – “No spacecraft has ever gone through the unique region that we’ll attempt to boldly cross 22 times. What we learn from Cassini’s daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve. This is truly discovery in action to the very end.”

These videos give me goosebumps. Oh Cassini, know your service to humanity mattered.

Timeline of Cassini Mission – https://saturn.jpl.nasa.gov/the-journey/timeline/#saturn-orbit-insertion

 

Cassini’s Curtain Call


NASA’s unassuming civil servant Cassini has a thing or two to prove. Before graciously accepting an inevitable and long overdue retirement -Cassini   obligingly agreed to traipse through daunting plumes of ice and water vapor, allowing mankind unprecedented insight into ice plumes erupting from the south pole of Saturn’s moon Enceladus.

Eighteen years after launch, seven years en-route to Saturn, eleven years exploring Saturn and her moons, two mission extensions beyond wildest expectations – Cassini has nothing to lose. On October 28 this sentiment meant taking a dive at 31,000 kph to within 45 Km of Enceladus at the south pole, directly into erupting “plumes” of icy vapor.

http://earthsky.org/space/does-enceladus-support-life-7-key-facts?utm_source=EarthSky+News&utm_campaign=1f5a27b312-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-1f5a27b312-393970565

Below – seven facts about Cassini/Enceladus from earthsky (linked above)

1. Early in its mission, Cassini discovered Enceladus has remarkable geologic activity, including a towering plume of ice, water vapor and organic molecules spraying from its south polar region. Cassini later determined the moon has a global ocean and likely hydrothermal activity, meaning it could have the ingredients needed to support simple life.

2. The flyby will be Cassini’s deepest-ever dive through the Enceladus plume, which is thought to come from the ocean below. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.

3. The flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.

4. Cassini scientists are hopeful the flyby will provide insights about how much hydrothermal activity – that is, chemistry involving rock and hot water – is occurring within Enceladus. This activity could have important implications for the potential habitability of the ocean for simple forms of life. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.

5. Scientists also expect to better understand the chemistry of the plume as a result of the flyby. The low altitude of the encounter is, in part, intended to afford Cassini greater sensitivity to heavier, more massive molecules, including organics, than the spacecraft has observed during previous, higher-altitude passes through the plume.

6. The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions — or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below.

7. Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.

Linked below, NASA’s Jet Propulsion Laboratory definitive guide to Cassini.

http://saturn.jpl.nasa.gov/

Ponder the exquisite magnificence of Cassini’s accomplishments.

Cassini’s Final Dione


A unassuming civil servant named Cassini has spent 18 dutiful years poking about the cosmos. Her passport stamps – Saturn, Phoebe, Titan, Enceladus, and Venus, joined last week by Dione.

This view from NASA's Cassini spacecraft looks toward Saturn's icy moon Dione, with giant Saturn and its rings in the background, just prior to the mission's final close approach to the moon on August 17, 2015. At lower right is the large, multi-ringed impact basin named Evander, which is about 220 miles (350 kilometers) wide. The canyons of Padua Chasma, features that form part of Dione's bright, wispy terrain, reach into the darkness at left. Image credit: NASA

This view from NASA’s Cassini spacecraft looks toward Saturn’s icy moon Dione, with giant Saturn and its rings in the background, just prior to the mission’s final close approach to the moon on August 17, 2015. At lower right is the large, multi-ringed impact basin named Evander, which is about 220 miles (350 kilometers) wide. The canyons of Padua Chasma, features that form part of Dione’s bright, wispy terrain, reach into the darkness at left. Image credit: NASA

Dione hangs in front of Saturn and its icy rings in this view, captured during Cassini's final close flyby of the icy moon. Image credit: NASA/JPL-Caltech/Space Science Institute

Dione hangs in front of Saturn and its icy rings in this view, captured during Cassini’s final close flyby of the icy moon. Image credit: NASA/JPL-Caltech/Space Science Institute

Cassini’s farewell to Dione allows for scheduled encounters with Enceladus on October 14, 18 and December 19. From December until mission conclusion in late 2017, Cassini plans to visit Daphnis, Telesto, Epimetheus, and Aegaeon, rounding out meticulous exploration of dignitaries among Saturn’s 63 or so moons. Below, Cassini’s timeline and link to NASA’s Casssini Mission –

http://saturn.jpl.nasa.gov/interactive/missiontimeline/

Deep Sea Diving on Enceladus


One thing science agrees upon – life as we know it couldn’t exist without water. A perfect storm of cosmic happenstance providing the watery depths “life” needed to take root. Millions upon millions of years simmering below the surface – diversifying, specializing, evolving – a watery lab imperative for life’s first twitch.

In 1997 the Cassini mission set off to study Saturn – primary objectives were better understanding of Saturn’s rings and exploration of her largest moon – Titan. Saturn’s tiny moon Enceladus ruffled scientific eyebrows when Cassini photographed active eruptions of icy vapor along fractures in the south pole and dubbed them “tiger stripes”.

Suspecting Enceladus might be hiding a liquid ocean, gravitational pull was studied as a means to understand the mass. The “tiger stripes” region of Enceladus’s south pole didn’t match in relation to the rest of the moon – the only plausible explanation for missing mass – a body of liquid, believed to churn 50 Km. below the surface.

http://earthsky.org/space/hidden-ocean-discovered-on-saturns-moon-enceladus

Pondering proof of liquid oceans miles below the surface of a distant frozen moon, plasters a grin on my face. Life requires water – what it does after that is anyone’s guess. Extremophiles eek out an existence in earthly places toxic or impossible for higher life forms to thrive. Arctic ice, underwater thermal vents, pockets of underground methane gas – all contain organisms known as extremophiles. I see no reason why a sub surface ocean on Enceladus couldn’t do the same.

http://www.dailygalaxy.com/.a/6a00d8341bf7f753ef0168e9452337970c-pi

Heat “output” beneath Enceladus south pole.

A link to Extremophiles…..

http://serc.carleton.edu/microbelife/extreme/extremophiles.html