Prof. Wickramasinghe and his colleague (can't be bothered to look the name up) are to be admired for such devotion to that idea of the great Hoyle. I found parts of their argument to be, if not convincing, intriguing.
The bits about 'more hospitable than the Arctic or Antarctic' were over-stated (what happens to that at or anywhere near aphelion, although it is easy to imagine survival as spores or virus-like things), but the other things they were saying were interesting.
Noone here knows if they do or do not have any valid points. Same for the ESA. It seems to me that some of the points they make are valid. Sure, not proof, worth a thought.
Anybody else suffer through Ben Gregford's 'Heart of the Comet'?
An awful novel, I have never re-read it, but haven't thrown it out. It is a great one for a very critical essay, more on the social and ethnic propaganda in it than the physics, mainly well worked out. Strongly favourable review in the New York Times. I want to write that critical essay one day.
A mission with a crew goes to ride a comet, the comet is infested with inimical life, the plot is brain-dead, and it is full of propaganda re. the human riders. If you have read it and think of the central protagonist in particular, you will understand.
A much better one on a related theme is a very short story by Ken McLeod (sp?), called 'The Oort Crowd', it was originally published in Nature, they had a stage of publishing very short stories. The dry wit is beautiful, recommended to any fiction-reading regtard, short and sharp.