The Mysterious Universe by Nigel Henbest. Yes it's an oldie, but when it's only $2 from the Lifeline bookshop it's a goodie!!
Another Lifeline goodie was Roger Moore's Travellers in Space and Time, the way it's written is amazing, he takes you on journey from the Sun through the Solar System and out into the depths. Such a great read that gets the imagination working, I highly recommend it