A good read and although written decades ago, is still very much relevant today. The book was made into a film starring Jodie Foster and I watched this before reading the book. There is, however, so much more in the book. It is an exciting prospect to think that all of this could be true and that there must be many more advanced civilisations in the universe that haven't made contact with us yet. Or have they in ages gone by?
It shows the dilemma we would face on earth if this happened and debates religion vs science quite nicely. It is also good to see how it unifies the people of earth in the face of the unknown- ie friend or foe?