I believe that together with "Death of grass" and "Day of triffids", this book is one of the most important British SF works of the 50s and as the other two, it resisted quite well to the passage of time. Written in 1957 by a real life scientist, Sir Fred Hoyle, a renowned astrophysician, "Black cloud" tries to stick very close to the scientific realities, even when describing things and events unheard off (at least for now).
As the title indicates, the story turns around a very large and very mysterious dark cloud of interstellar dust approaching the Solar System at great speed. The size of the cloud is immense and even if it seems to go straight towards the Sun, it is large enough to also touch the Earth. Scientists from United Kingdom and USA struggle to understand what exactly is the cloud and what will be consequences of its arrival. No more information will be given here to avoid spoilers.
The strong point of this book is that it keeps surprising us at every new chapter. Virtually nothing we assume in the beginning will linger until the last pages. Hard science is quite present and it gives to this book a considerable stregth. There is some very British humor and the dialogues are quite good. The reading is easy and I really was sorry that the story ended so fast, as the book is not very long.
The one point I did not totally like was the presentation of British and American politicians. For both countries they are described as powerless and quite stupid cowards who as soon as they can turn into vicious and madly irresponsible bullies. It is everybody's right to dislike the politicians but in this book their descriptions are so grossly exagerated that normally I would drop the rating by two stars. But on another hand I realise that to keep the story together and focus the tale on the scientists the author simply needed to dispose quickly of political interferences - and therefore I take away only one star.
I enjoyed reading this book a lot and I recommend it to anybody interested in science-fiction.