On Under Alien Skies

It took me some time to get into this book, but I found it really rewarding. It almost feels too easy, even a little boring, at the beginning, with the moon and Mars — you wonder for a moment whether the whole book will only cover the color of the sky and differences in gravity. But Plait gradually steps it up, offering more detail and more illuminating angles on the universe; his discussion of binary systems (especially “P-type systems”) was especially challenging for me, and the writing on nebulae wasn’t the easiest either, though I managed to make sense of it. (As an aside, what really stands apart here are the footnotes — they’re great.)