Having apparently given up hope of simulating life in a laboratory, with the
SETI heavens remaining silent, and with Mars looking less like a candidate
for life, exobiologists are transferring their hopes towards Jupiter's moon,
Europa.
Note the implicit assumptions that life is just like any other physicochemical
process:
"And where there is heat and water, the odds for life taking hold should
skyrocket."
But there is plenty of "heat and water" here on Earth, in a wide range of
habitats, from Pole to Equator, and from mountain heights to the depth of
the sea. And if that fails, scientists can simulate almost all imaginable
conditions in the laboratory. So why should it work on Europa?
However, lest it be thought I am anti-science, I wish to state I am a
*supporter* of these origin of life experiments and quests. If their success
would imply that the materialist-naturalist paradigm was right, their
continued failure would imply that it is wrong!
Steve
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http://space.com/news/planetarymissions/europa_story_991109.html
Space.Com
[...]
Move Over Mars -- Europa Needs Equal Billing
By Leonard David
Washington Contributing Editor
Nov 10 1999 06:31:55 ET Europa, a moon of Jupiter, appears to
have vast quantities of liquid water below its icy surface, making
this world a top candidate in the search for exobiology -- life
beyond Earth -- a scientific panel reported today.
The National Research Council (NRC), an advisory arm to the
nation on science, released its report: "A Science Strategy for the
Exploration of Europa." It recommends to NASA that Europa be
given priority equal to Mars in planning for future exploration.
The NRC's Committee on Planetary and Lunar Exploration
(COMPLEX) issued the scientific report. Ronald Greeley, chair of
COMPLEX, told space.com that "the potential for understanding
environments that can support life is high on Europa. In some
respects," he added, "Europa could be a better target for
exobiology than Mars."
Greeley said Europa is believed to sport an internal heat source,
primarily driven by the gravitational push and pull on the moon --
called tidal effects -- as it circles gigantic Jupiter. "In contrast, we
don't know about any internal heat generated on Mars," he said.
According to the NRC report, Europa may contain a global ocean
of liquid water more than 62-miles deep, and covered by only a
thin layer of water ice. And where there is heat and water, the
odds for life taking hold should skyrocket.
"As a result of the likely existence of liquid water, at least on a
transient or intermittent basis, Europa has the potential for life to
exist below its surface," the report says.
Now on duty around Jupiter is the Galileo spacecraft. Dispatched
from the space shuttle Atlantis in October 1989, Galileo has been
studying Jupiter and several of its moons for nearly four years.
Just last October 11, Galileo slipped by another moon of Jupiter --
volcano-laden Io. A similar flyby of Io by the probe is slated for the
end of this month. But during this encounter, Galileo is also slated
to snap photos of Europa from a perspective never viewed before,
Greeley said.
What next for Europa?
"Our report outlines a rationale to search for life on Europa and
details the kinds of measurements to address the question of life
on Europa through a series of missions," Greeley said.
The NRC report recommends the need for a step-by-step program
of exploration. Work is already underway on a Europa orbiter
spacecraft at the Jet Propulsion Laboratory in Pasadena,
California. That mission should determine whether a global ocean
of liquid water exists beneath the moon's icy exterior.
Follow-on work at Europa, the NRC report urges, should focus on
first landing a package of instruments on the jovian moon. If sub-
surface liquid water is detected, and can be breached, an
instrumented probe to scout for life in the liquid water should then
receive priority, the NRC study concludes.
[...]
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"According to the modern theory (called neo-Darwinism), changes occur in
organisms by mutations of genes. This leads to the existence of variation
amongst individuals. Some of these individuals may survive more
successfully than others (called natural selection), thus producing more
offspring with their new features. Gradually these new features will extend
throughout the population. If, however, the population is isolated from
others differences cannot spread, and over a period of time two varieties
come to exist. Only small changes to organisms have been actually
observed to occur by this mechanism. e.g. Industrial melanism, resistance
to antibiotics and insecticides. Evidence for larger changes must be
deduced from the fossil record. ("evolution", in Heffernan D.A., "The
Australian Biology Dictionary", [1987], Addison Wesley Longman
Australia: Melbourne, Australia, 1996, reprint, p87)
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
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