From: "Keith F. Lynch" <kfl at KeithLynch.net>
To: WSFA members <WSFAlist at KeithLynch.net>
Subject: [WSFA] Re: "NASA ignores Arthur C. Clarke, may attempt landings on Europa"
Date: Mon, 12 Dec 2011 21:09:42 -0500 (EST)
Reply-To: WSFA members <WSFAlist at KeithLynch.net>

"Mike B." <yahoo at omniphile.com> wrote:
> Keith F. Lynch wrote:
>> Interesting.  I wonder just how thick the ice is.  Would scuba diving
>> be possible there?  I know that scuba dry suits allow diving in
>> freezing-cold water, and that special gas mixtures allow diving at
>> pressures up to 50 atmospheres.  And since Europa's gravity is a lot
>> lower than Earth's, that allows for a considerable thickness of ice
>> before the pressure under the ice gets too high.

> http://www.lpi.usra.edu/resources/europa/thickice/
> says at least 19 kilometers.

Too bad.  The record scuba dive is only 330 meters.  Adjusting for
the lower density of ice, the lower gravity of Europa, and the fact
that you're starting from a vacuum rather than from Earth sea-level
pressure buys you at most 3 kilometers.  But perhaps the ice is
thinner in spots, and perhaps further advances in scuba will allow
deeper dives, so it might still be possible.

>> I know of at least three other places in the solar system (other
>> than Earth, of course) where a spacesuit shouldn't be needed:

>> * Floating in a balloon over Jupiter.  ...

> Assuming the radiation doesn't bother you.

You'd need sheilding on the way there, especially when you get close
to Jupiter.  But there should be little or no radiation once you're
in Jupiter's atmosphere.  (Except for solar ultraviolet, since Jupiter
has no ozone layer.  Similarly in Venus' atmosphere.)

Radiation is really fierce on Europa's surface.  But under the ice
there's probably less radiation than anywhere on Earth.  Nothing but
neutrinos is likely to penetrate kilometers of ice.  And since the ice
and the water under it are likely to be much lower in dissolved solids
-- including radioactive potassium 40 -- than Earth's oceans, that
would be the ideal location for any experiments that need a very low
radiation background.  Even the neutrino flux is much lower there than
on Earth, since it's much further from the sun.