Bruce, Bob, et al.,
If the Europa orbiter goes ahead as planned, they should paint it pink, because it will be one of the best pink Cadillacs NASA-JPL will have ever flown. I'm all for space exploration and full employment, but let's get these guys and gals to do something really courageous and beneficial for science in our lifetimes, like launching some kind of lander(s) on the Europa surface. Landers with corers or a set of penetrator probes will be guaranteed to find something important and useful about the composition of that moon, lifeless or not, and probably in the first 5 minutes after impact. Why was a lander probe such an "easy, no-brainer" decision for the Cassini mission to Saturn/Titan, and so much ado here? Gary >----- Original Message ----- >From: "robert_pappalardo" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Sunday, June 09, 2002 11:00 AM >Subject: [jupiter_list] Re: future Jupiter-Europa exploration > > >> --- In [EMAIL PROTECTED], "Bruce Moomaw" <[EMAIL PROTECTED]> wrote: >> >> > > Still, I'm surprised that people think an ocean might not be >> present. I >> > > almost wonder if that group are so fixated on the ice >> diapirism model of >> > > chaos formation that they don't *want* there to be an ocean. :) >> > >> > I definitely wouldn't say that -- Pappalardo has always >> emphasized that the >> > convective ice-diapir model works equally well whether there's >> an ocean >> > beneath the convective ice layer or not. >> > ____________________________ >> > >> >> Not true, actually. The "thick-shell" model presumes an ocean at >> depth, i.e. one that does not directly communicate with the >> surface, but which may have indirect expression at the surface. >> >> Hoppa et al.'s explanation of cycloidal fractures essentially >> demands an ocean (they say at 1 km depth, but it could just as >> well be at 10's of km for the diurnal stress mechanism to >> operate). Schenk's recent cratering piece suggests multi-ringed >> structures have sensed the ocean (a reassonable hypothesis, >> though he doesn't demonstrate this conclusively). Plus the >> magnetometer result is very convincing. Note that the Hoppa et >> al. model was in its infancy when the 1999 "ocean paper" JGR >> tome was written by myself and the Galileo imaging team (which >> urged caution regarding an ocean's existence), and the >> magnetometer result was not yet confirmed. >___________________ > >Ah. So you do now think that an ocean is a near-certainty? I was told by >somebody (can't remember who) at the December Decadal Survey meeting that >you still thought there was about a 25% chance against it. The more certain >an ocean looks now, the more the case for the next Europa mission being a >Europa orbiter (rather than a Jupiter orbiter) seems to weaken. And I >really think that will be the single most urgent question to be answered by >the Decadal Survey report -- I now take for granted that they'll strongly >favor the "New Horizons" Pluto mission, and the best approach to future Mars >exploration seems to be to wait for the results from the missions through >2005 or 2007 before planning post-2009 exploration in any detail. > > >== >You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] >Project information and list (un)subscribe info: http://klx.com/europa/ == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
