Re: We seem to be unable to adequately sterilize our spacecraft
Oh if only we had thought to do trials in a similar sort of situation here on Earth. Except we did, in the Lakes under the Antarctic Ice. The Russians did it and the Americans (I think, might have had European input too) and LIFE was found an analysed and the difficulty of the taks assessed and design efforts for how to drill the Europan ice go on apace.
We have to hope the ice, top layer at least isn't as hard as the ice on that comet which got landed on. The testing hammer broke at 'harder than concrete'. Europan ice should be younger and more turned over than the comet's but if they happen to land on the oldest section . . .