Close Encounter with Enceladus
 
Oct 27, 2015: Over 980 million miles or about 1.6 billion kilometers from
home, NASA's Cassini spacecraft hurtles through the starry expanse of space.
From its vantage point orbiting Saturn, Earth is nothing more than a miniscule
pinprick of light not unlike the stars framing the gorgeous ringed planet.
 
Cassini has been orbiting Saturn since 2004, and it has made dozens of flybys
of Saturn's intriguing moons. Its next close encounter with Enceladus on
October 28, 2015 promises potentially exciting results.
 
http://youtu.be/nts-bkhoMt4  
NASA's Cassini Spacecraft is about to make a daring plunge through one of the
plumes emerging from Saturn's moon Enceladus.
 
Enceladus boasts an icy, ostensibly barren landscape riddled with deep
canyons, dubbed "tiger stripes." Underneath its icy exterior churns a global
ocean, heated in part by tidal forces from Saturn and another moon, Dione,
with seafloor vents expelling water at at least 194 degrees Fahrenheit. Plumes
of water vapor and icy particles jettison from its surface in geyser-like
spouts, hinting that there is much more to this snowy moonscape than meets the
eye.
 
Cassini will be soaring through the jets located at the moon's south pole,
only 30 miles above the surface.
 
"Although the October 28th flyby won't be the closest we've ever been to
Enceladus, it is the closest flyby over the south pole and through the plume,"
says Linda Spilker, the Cassini Project Scientist at the Jet Propulsion
Laboratory. "We'll be exploring in situ a region of the plume that Cassini has
never sampled before. This is very exciting for me!"
 
So what causes these plumes, and why are they so important? Enceladus' vast,
subterranean oceans may be fizzy and full of gas. When the gas and icy
particles rise to the surface, they are expelled in plumes shooting from the
"tiger stripes." In the words of Linda Spilker, the process is similar to
"shaking up a bottle of soda; the gas has nowhere to go but up and out."
 
However, the plumes are more than just gas and water: samples show that they
also contain many of the building blocks essential to Earth-like life. This
lends itself to the exciting possibility that organisms similar to those that
thrive in our own deep oceans near volcanic vents exuding carbon dioxide and
hydrogen sulfide might exist on Eceladus. Although it is still too early to
know exactly how complex potential Enceladus' lifeforms could be, scientists
speculate that at the very least microbial life is a real possibility.
 
In the future, a different spacecraft may journey across the solar system to
visit icy Enceladus. This spacecraft, unlike Cassini, could be designed to
land on Enceladus' surface, near one of its "tiger stripes." Such a lander
would be able to take samples more directly, bypassing the plume altogether.
 
"Ideally, it could take samples from the edge of one of the tiger stripes,"
speculates Spilker. This would ensure that any microbes being expelled from
Enceladus' interior would be more plentiful and easier to collect.
 
Until then, flybys are the best we can do. And the next one should be very
good indeed. Tune in on Oct. 28th!
 
Credits:
 
Author: Ferris Molina | Editor: Dr. Tony Phillips
 
 
Regards,
 
Roger

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