Dark Matter and the Dinosaurs
Dark Matter and the Dinosaurs is a fun little pop-science book that ranges widely over a bunch of topics connected by the fact that they are cool. The book, for example, has an interesting section pointing out the difference between dark matter and dark energy, as you might expect from the title.
The author also has interesting things to say about a host of other topics, such as why there is something rather than nothing and the relationship between cosmos and cosmetics.
Even though the universe is expanding, neither atoms nor planets are getting any bigger. Only the space between galaxies is expanding. That was another tidbit that was new to me.
There is also a very nice section on how archaic terms such as meteorology, which is not the science of meteors, and parsec, which is a complex way of saying about 3.3 light years, are still around confusing everyone.