Fact and Fancy by Issac Asimov.
Isaac Asimov wrote a monthly science essay column for The Magazine of Fantasy and Science Fiction (F&SF) and the book Fact and Fancy collects the first seventeen of those essays, dating from between 1959 and 1961 (there are many more of these F&SF collections and I will be working my way through them).
Rather than enumerating and summarizing all the essays (which is done finely here) I’ll just say that the focus is on Earth, orbital mechanics, astronomy, and skepticism. The essays are each sufficiently short (about 10 pages) that to summarize them would be essentially to “spoil” them, for the joy is in Asimov’s explanatory power. These extend from discussing the angular sizes of astronomical bodies to describing what it would be like to live in a double star system to the view available on various bodies around the solar system. They can also be on unconventional or uncommon topics, like why phosphorus is the bottleneck for life or how far you’d have to go and yet still be able to make out the Sun.
The last essay is interesting in that (like the others) it was written shortly after the launching Sputnik when there was much hand-wringing about the level of science education in the United States and the backlash from those working in the humanities that had a scornful view of science. Asimov clearly detests this attitude (rightly I’d say), citing it as a long-term recipe for disaster and just a genuinely ridiculous position (why should an exploration of the humanities exclude on principle an investigation of Nature?). I wonder how this situation has carried to the present day, when it seems there’s just as much contempt flowing in the reverse direction, towards those who focus on the humanities to the exclusion of the sciences. The essay also points out the ludicrousness in sorting and judging people based on what culture they consume (as in somebody who reads comic books would feel ashamed talking to somebody who reads classical Greek).
I look forward to the rest of the essay collections, of which View from a Height is next, though he has an earlier non-F&SF collection called Only a Trillion that I’ll be tackling next. These reviews are of course off the cuff reactions pretty much immediately after I finish the books. For a more long-term look back on Fact and Fancy, there’s this.