Re: Heat

[JHByrne]

In a message dated 11/1/2002 12:55:48 AM Alaskan Standard Time, [EMAIL PROTECTED] writes:

The pressure of the ice will be similar to that which the probe would
encounter in a comparably deep layer of liquid water -- actually slightly
less, since ice's density is only 97% that of water.  Since Europa's gravity
is only 13.5% of Earth's, the pressure at 20 km depth of (uncontaminated)
ice on Europa equals that at a depth of 1.31 km in uncontaminated Earth
liquid water.  However, the evidence is growing that Europa's ice and water
may be VERY briny -- perhaps as much as 30% various salts by weight -- and
that, of course, would substantially increase its density and thus its
pressure.

As for the meltwater space around a Cryobot: the pressure will be similar
all around it -- so there will be virtually no mechanical pressure trying to
squeeze the Cryobot back up out of the hole.

You know, now we are talking practical considerations of ice pressure, which is a great thing, as it is one more step that must be considered in the actual probe.  If we can figure out a way to drop a terrestial probe down 200' in a glacier, that would presumeably tell us something about how a similar probe on Europa would react at a quarter mile down.  It's a significant start.

-- JHB