Thank you to Netgalley and to the publisher for providing me with an ARC of Alien Earths! Wow, this book packs a lot of information into a relatively small package. I learned so much more than I had anticipated not just about current efforts in astrobiology, but about the history of our galaxy and our planet. While Dr. Kaltenegger covers a lot of information in this book, however, I will say that it felt a bit disjointed at times. Each chapter has “mini-chapters” that focus on a mix of specific topics and Kaltenegger’s personal experiences. While a good tool for moving between topics, I did fail to see the connections at times. I was also hoping to read more directly about astrobiology and current efforts, and I did not realize that a good portion of this book talks more generally about our solar system/galaxy and Earth’s history. As someone personally very interested in astrobiology and the search for life, I will say that I was hoping for more out of this book. However, for those more generally interested in these topics, this will make for a fantastic and comprehensive introduction about what we know and how we know it when it comes to astrobiology and broader astronomy.