From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Apr 30 2008 - 07:44:16 PDT
Jupiter's Europa - Will It Provide the 1st Proof of Extraterrestrial Life?
To quote:
With Jupiter being the largest planet in the solar system, its tidal
stresses on Europa create enough heat to keep the water on Europa in a
liquid state. More than just water is needed to support life. Tides also
play a role in providing for life. Ocean tides on Europa are much greater in
size than Earth's with heights reaching 500 meters (more than 1,600 feet).
Even the shape of the moon is stretched along the equator due to Jupiter's
pull on the waters below the icy surface.
The mixing of substances needed to support life is also driven by tides.
Stable environments are also necessary for life to flourish. Europa, whose
orbit around Jupiter is in-sync with its rotation, is able to keep the same
face towards the gas giant for thousands of years. The ocean is interacting
with the surface, according to Greenberg, and "there is a possible biosphere
that extends from way below the surface to just above the crust."
"The real key to life on Europa," Greenburg adds, "is the permeability of
the ice crust. There is strong evidence that the ocean below the ice is
connected to the surface through cracks and melting, at various times and
places. As a result, the biosphere, if there is one, includes not just the
liquid water ocean, but it extends through the ice up to the surface where
there is access to oxidants, organic compounds, and light for
photosynthesis. The physical setting provides a variety of potentially
habitable and evolving niches. If there is life there, it would not
necessarily be restricted to microorganisms."
...
The future NASA DepthX mission to Europa, scheduled for 2019, is a
mushroom-shaped machine, an underwater hydrobot that 'thinks' for itself.
DepthX is currently undergoing tests in one of the world's deepest flooded
cave systems -the El Zacaton cave complex in Mexico- to simulate penetrating
the Europa's ice-covered seas. The next version of the machine will be
tested in Lake Vostok, a deep ice-covered lake in the Antarctic. The craft
sent to Europa would use nuclear power to melt through the 10km of ice that
cover the moon's ocean. The mission will be one of the most complex ever
attempted by the American space agency NASA.
Full article here:
http://www.dailygalaxy.com/my_weblog/2008/04/jupiters-europa.html
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