Friday, July 29, 2011

Enceladus rains water vapor on Saturn - how about microbes?

Badly answered question: 1. Is there life (as we know it) on gas giant planets?

Better answered questions: 2. Can life originate on gas giants? and 3. Can life survive on gas giants?

What I've seen of pop science, and my impression of Planetary Protection standards for spacecraft, is the assumption that because the answer to #2 seems to be "difficult", then the answer to #1 is "unlikely". But what if you drop living microbes through space and into the gas giant atmospheres?

That could be happening on a regular basis with Enceladus shown to drop water vapor from its geysers on to Saturn's atmosphere (blog post at link, pdf of article in the blog post). Enceladus probably has a near surface ocean feeding geysers through cracks in the ice. If it has life, then microbes are also being shot out as the geyser jets freeze.

The water vapor connection to Saturn doesn't necessarily establish that water ice particles will get there, or get there in the same short time frame (<2.5 months) as the vapor, but it makes it more plausible. And there's always the impact delivery of ice chunks from Enceladus to Saturn as a mechanism.

While microbes couldn't survive the deep level heat (which is what would stop life from originating on gas giants), if they can survive long enough to reproduce and randomly spread, then some descendant microbes can escape destruction. All they could need is some weather patterns keeping them out of the deep layers for weeks, unlike the millenia that would be needed for life to originate there.

Besides being interesting and a potential target for astrobiology, there are some policy implications to this. Crashing the Galileo orbiter into Jupiter may have been a mistake - better to have crashed it into Io, Callisto, or Almathea. The plan to eventually deorbit the Cassini mission into Saturn is also mistaken, when the dead-surface moon Mimas makes a better target.


John said...

Sorry, off topic.

Any notice of this: "Arctic scientist who exposed climate threat to polar bear is suspended. US government conducts 'integrity inquiry' on federal biologist amid lobbying by oil firms for Arctic permits"?

John Puma

Angliss said...

But we don't want to contaminate those silicon-based lifeforms like the horta, Eli!

Brian Schmidt said...

All the more reason not to drop silicon computers/space probes on them!


There is even danger of Newscorp contamination of the Saturnine surface:

A Snowball Under the Sun
> March 14, 2006; Page A18
> When NASA's Cassini mission blasted off for Saturn in 1997 bearing
> the Huygens probe, the ringed planet had 18 moons, the first five
> spotted in the 17th century by the astronomers whose names the
> mission honors. It's not their fault they missed Enceladus. Baroque
> astronomers peered through telescope glass about as transparent as
> a bottle of crusted port.
> Enceladus, the bright little moon now making headlines for its
> spouting geysers, had to wait until 1789, when Royal Astronomer
> John Herschel had the benefit of achromatic lenses clear as spring
> water, as well as Sir Isaac Newton's newfangled reflecting
> telescope. Such instruments racked up another 13 Saturnian
> satellites in the three centuries that followed. But even with the
> best and biggest telescopes, Enceladus is still not much to look
> at. Seen from Earth, it's the closest thing to a snowball under the
> sun.
> Frosty white, and featureless at a distance, it is also rather
> small. While Titan, which Huygens discovered, is a comparatively
> titanic 2,500 kilometers in diameter, Enceladus is a modest 500 --
> a dozen like it could hide behind our moon. But between Cassini's
> liftoff and arrival, earthbound astronomers used smart optics and
> small telescopes on space probes to add more than a baker's dozen,
> bringing the waxing list to a mind-bending 35: Albiorix, Atlas,
> Calypso, Daphnis, Dione, Enceladus, Epimetheus, Erriapo, Helene,
> Hyperion, Iapetus, Ijiraq, Janus, Kiviuq, Methone, Mimas,
> Mundilfari, Narvi, Paaliaq, Pallene, Pan, Pandora, Phoebe,
> Polydeuces, Prometheus, Rhea, Siarnaq, Skadi, Suttung, Tarvos,
> Telesto, Tethys, Thrym, Titan and Ymir.
> In addition to enough mythical Greeks to populate several Boy Meets
> Nymph operas and Scandinavians sufficient for a sitcom sequel to
> Götterdämmerung, the cast includes paddle-on Inuit sea deities and
> a refugee from the Celtic Otherworld. This is less a reflection of
> multicultural PC than sheer exhaustion. The demiurge drain
> elsewhere in the solar system has cleared the shelves of handy
> Hindu handles, Gallic godlets and the pan-African animist pantheon.
> Islam and Judaism are no help at all, and Asterix has long since
> been taken for a ride by an asteroid. Even postmodern astronomers
> blanche at the tentative name of the biggest ball of ultracold
> black wax in the Kuiper belt. If Xena achieves textbook
> immortality, there's no polite way to stop the declension of her
> mooning companion as -- what else -- Gabrielle.
continues past 4kbyte below


Pardon my prolixity, but the preceding beginning has a relevant end:

" It can only get worse as telescopes get better. Saturn's latest
squeeze, Daphnis, is such a midge she could be plunked down like
the Flushing Perisphere for a War of the Worlds Fair in Kashmir
without blocking the view of K2. Mundilfari is even smaller --
three and a half miles must be a galactic record for vertically
challenged fathers of sun gods. If telescopes keep growing, and
moons shrinking at their present rate, before the eon is out Texans
may be using minor satellites to shoot quail.
Now that we have established that Enceladus is an object of very
respectable size, what's all this about life out there? Not a whiff
has been discovered, despite the presence of liquid water -- but
though there is as yet no sign of life in the neighborhood, NASA is
understandably chuffed about discovering the neighborhood itself.

Yes, it's cold out there and there's no kind of atmosphere, except
at the south pole where, sure as Old Faithful, the place has
geysers galore, as in water gushing out of the ground and into
direct sunlight. Just what makes this snowball spout remains an
energetic mystery. Enceladus is way too light in both senses of the
word for either solar heating or radioactive decay to be warming
its core. It is also too far from massive Saturn for tidal forces
to be flexing warmth into its frigid mix like a mass of sorbet or
salt water taffy in mid-manufacture. Saturn's nearly identical ice
moon, Mimas, takes more tidal stress, yet remains adamantly frozen.
It has been so for a very long time, for its profoundly cratered
surface boasts a black eye a third of its diameter, while Enceladus
has the fresh-from-a-face-job look of something whose tectonic skin
is rolling up and over at a goodly rate.
So something is warming it up big time. But what? We face a hot
debate as to what antediluvian energy source allows liquid water to
bubble up out where frigid liquid nitrogen serves as morning dew.
For the moment what matters is that the water in question is likely
wet a stone's throw beneath the surface -- a safe bet since
Enceladus's gravity, 1% of Earth's, is such that a girl scout could
pitch a salmon half a mile. So even if this snowball is utterly
sterile today, its south polar fissures may present places where a
patient ice fisherman in a space suit could lower away a bald Chia
Pet and bring up an alfalfa salad. This is not much of a First
Contact story by H.G. Wells, Robert Heinlein or Truffaut-Spielberg
standards, but cheer up -- at least we're not on the menu. Yet.

Steve Bloom said...

Microbes? I'll see your microbes and raise you Roy Spencer.

Flogistix said...
This comment has been removed by a blog administrator.
EliRabett said...

John, Eli has had several posts on Boemerangate. just google

Monnett Rabett and there are loads of links. The story has gone quiet for a few months now tho.