Europa : Fact, Myth, Perspective
Ice or Ocean, Crete and Tyre, Dry to None
by Duane Dunkerson
Fact : Maybe
In 1610 both Galileo and Marius sighted the four principal moons
of Jupiter. Europa is one of the four and is the smallest of the
four. It is second in position outward from Jupiter.
Europa had been a point of highly reflective light in orbit about
Jupiter until the spacecraft, Voyager, showed mostly grooves and
ridges on its water-ice surface. Decades later the Galileo spacecraft
has confirmed what Voyager saw for us. Galileo has brought more
to our attention. We have become mostly interested in the amount
of water that may be present and in the possibility of life below
the surface in conjectured vast seas of water.
Brother Guy Consolmagno hit upon both possibilities of abundant
water and life on Europa. His 1975 thesis proposed that Europa
was a moon with an icy covering and an ocean below that frozen
crust. In an appendix for this thesis he touched lightly on the
possibility of oceanic life below the surface.
He pointed out that John Lewis in 1971 had noted that the moons
of Jupiter and Saturn were most likely of rock and water ice.
Their surfaces were bright. By the middle 1970's, infrared spectra
of Europa had been obtained. The spectra matched those of water
ice. Father Guy thought Europa's water was nearly all melted with
a thin icy crust. He proposed about 100 km of water.
He talked briefly with Carl Sagan at a scientific conference
about his thesis. Sagan coolly inquired how life-giving energy
could be provided without sunlight penetrating the icy crust?
Father Guy briefly thought how about life by means of energy from
a volcano? No one had seriously heard of such a thing.
In the late 1970s oceanographers here on Earth found volcanic
vents under the Atlantic that had colonies of life - living by
means of energy supplied by the chemical reaction between lava
and the seawater into which the lava flowed. In 1983, a group
of scientists also thought life was in Europa, that heat was supplied
by tidal action, and that lava flows gave life.
They were giving life in an underground ocean, second to none
in size for the Solar System. Vast quantities of water could be
available. We don't want distilled water. We want salty stuff,
a brine made up of dead cells from a part of a living mass.
No taste tests have been done from the water in Lake Vostok but
many common and strange organisms have been found in ice cores
taken from above it. Lake Vostok, the size of Lake Ontario, lies
4 km under the ice of Antarctica. Apparently geothermal heat put
the water into liquid form. A Vostok-like ocean could be on Europa.
Perhaps there is also a volcanic heat source on Europa. If not,
or in addition to it, there may be tidal friction brought on by
Jupiter's gravitational proximity causing a tidal bulge that alters
shape and position to push-pull tidal forces.
A magnetometer on Galileo showed that a magnetic field for Europa
varies periodically. This can be explained by an electrically
conducting liquid like saltwater. Ice is not a good conductor.
Europa's magnetic field is a secondary one induced by and responding
to Jupiter's magnetic field.
Galileo also got good looks at Thera and Thrace. They are dark
terrain that may be local meltdown of the ice. They could be projecting
from the interior or they could be on their own, up in the ice
floes of Europa's surface.
Thin ice or thick ice? Lots of water? These and other questions
may have answers provided for by Europa Orbiter. This proposed
mission would have on board a radar capacity to measure the thickness
of the ice, establish if there is water below the crust that is
liquid, and assess tidal forces on Europa- if Europa has an ocean.
There is talk of later missions to dispatch remote-controlled
undersea craft to seek life.
Europa was the daughter of Agenor. He was a Phoenician. The Phoenicians
were ancient seafarers with a range all about the Mediterranean.
Europa is now immortalized on a moon that may allow for seagoing
voyages far beyond the maritime dreams of those ancient Phoenicians.
They traded with Cyprus, Egypt, India, Spain, and Africa. A famous
dye, from the murex snail, was a hot item. The Phoenicians also
had an alphabet of 22 consonants. It was contributory to the Hebrew
and Arabic writing. Carthage was theirs until 146 BC.
Cretans say, not they, but Zeus, as a white bull, took Europa
from her city of Tyre. She was taken by whatever agent to Crete.
Zeus gave her gifts. One of these gifts was a javelin that, if
thrown, never missed. We do not have a name for the javelin. Zeus
also gave her Laelaps, a dog, which never missed its meat. Europa
Orbiter could be favorably named as Europa's Javelin or as Laelaps.
Perspective : Raspy Water
Not so long ago life was preposterous - beyond earth. There was
a greatness and a delicacy here that most were sure could not
be duplicated. Perhaps Mars, as the abode of life as Lowell put
it, in the time of the Mars mania, cooled off a great many from
any expectant stance for life elsewhere in the Solar System.
Our telescopes and attendant apparatus could not find life beyond
us. Then spacecraft soared skyward and out to Mars and Europa.
A great deal of water may be at one or both places.
We aren't ready for life-not-as-we-know-it. We eagerly seek water
there. Once all was dead but us. The needle had gone over hard
right, very conservative views of life's elsewhere possibilities
were stated. Now the needle has pegged, it is slammed far left,
there are very liberal possibilities feeding on scraps of information.
We may be anticipating more than the life there - we may be dreading
a badly burnt earthbound psyche. We see ourselves parched, teetering
on dry stack of rocks, with a river in the distance. One river
would not be enough for the planet. The brilliant lies of the
anti-environmentalists can't provide enough room for us on the
banks of a single river. And so in the future
The latest transport from Europa releases gigantic splashes in
the sky. Like baby robins in a nest we crane our necks awkwardly
with mouths agape, flopped out, for a drop or two. We don't want
anymore of what is not the best of life, a grating, sandy water
We are all incomplete and deficient in the present. Gone away
into the past are the slender, not gaunt, ones. We have elixirs,
little better than what exudes from sebaceous glands. We lick
the water from the scales of a fish.
No more water hazards, or water clock, sand in the hourglass
is most appropriate. Water wagons are dismantled. The back-up
beeper on the water truck has no sound to make. Magical implications
of a long, relaxing shower are only read about.
We may need a bucket brigade from Europa. Never mind the occasional
exotic rotifer in the water. Drink it down. Don't gulp, enjoy
it for such a little while at least.
There are no natural manifestations of aquatic purity, no rapids,
all are pools, simmering in the heat. No breakers, no carafes
one could scoop into the freshwater surf.
What comes from the sky is a dry mist, insubstantial, we camels
of an enlarging desert see fullblown mirages of a persistent oasis
where the grass is not a painted green collection of tiny sharp
rocks. Super soaker, wetlands, spillways, the smell of rain -all
You don't splash any water on your face, what a waste. It goes
into the mouth. Better dirty than dead. Some dislike the slogan
and get to be too thirsty. Is that what some said? I can't hear
can't hear you
water's running. In a dream.