QUESTION:
It may be a bit premature, but with the success of the Pathfinder (and 
the new approach at NASA that made it possible), could an 
isotope-powered "Pathfinder II" fairly easily be sent to Europa or 
Titan?  Both seem to have more atmosphere (for braking) and a better 
chance for water, and maybe even a chance for life.

ANSWER from Mark Adler on July 14, 1997:
Titan perhaps, Europa no.  Europa does not have an atmosphere.

It turns out that we are launching later this year a probe to land on Titan  
as part of the Cassini mission--the Huygens probe, being provided by the  
European Space Agency.  Huygens will land simply using a parachute with no air  
bags or rockets, and is expected to survive the landing.  Titan's atmosphere  
being much thicker than Mars's allows a paratrooper-style landing.  It takes a  
while to get to Saturn though, and so Huygens will land on Thanksgiving in  
2004.

Mark Adler