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.

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.

Ponder the exquisite magnificence of Cassini’s accomplishments.

Alien Life By 2025 – NASA

On Tuesday April 7, NASA chief scientist Ellen Stofan spoke at a panel discussion on water in the universe. Stofan boldly stated “there will be strong indications of alien life within a decade and definite evidence of it within 20-30 years”.

“We know where to look, we know how to look” – Ellen Stofan

Exhale now if the possibility created notions of wide eyed “greys” or Starship Trooper “bug” armies. Life must first be seen from microscopic perspectives – confirmation of other-worldly life will likely arrive as microbes eking out existence right under our noses.

Simply looking for evidence of water in our solar system holds promise of life. We know that half of Mars was once covered in liquid ocean – likely for a billion years until the atmosphere degraded. Data from the Hubble Telescope suggests Jupiter’s moon Ganymede hides a saltwater ocean beneath thick icy exterior armor. Likewise Jupiter’s iconic moon Europa, and Saturn’s Enceladus.

Without a shred of doubt, confidence that irrefutable evidence of alien tenacity will manifest itself in my lifetime is unshakable. Pondering implications of such certainties leave me hopelessly buoyed, incapable of wiping a childish grin off my face.

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.

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.

Heat “output” beneath Enceladus south pole.

A link to Extremophiles…..