"From noted astronomy writer Phil Harrington comes this welcome one-of-a-kind guidebook. Harrington provides page after page of observing challenges that encourage the reader to test his or her observing skills with naked eye, binocular, or telescope. With its blend of clear, descriptive narrative and detailed finder charts, this book is a pleasure to use. Cosmic Challenge belongs on the bookshelf of every serious amateur astronomer." - Glenn Chaple, contributing writer Astronomy magazine
"If you're ready for the challenge, Phil Harrington has thrown down the gauntlet." - The Astronomical League
"I would heartily recommend this book.The book was three years in the making and it shows. A great deal of care and attention to detail has been spent. It is well written, has an interesting selection of objects suitable for all observers with varying degrees of difficulty, has good descriptions and nice charts. I don’t think it is intended to be a book to work through from start to finish, but there are many ideas and gems to alight on, so just dip through and you’re sure to find something of interest." – Callum Potter, J. Br. Astron. Assoc.
"Well presented, no nonsense, lots of content ... Overall, an interesting and attractive book that will keep most purchasers happy and which may, eventually, become very popular indeed." – Astronomy Now Online
"This is a book that will more than likely put you through your paces, whether you are an experienced amateur astronomer or a newbie...Cosmic Challenge is also a book worth reading for the sake of reading. It is well-written, with a pleasant, conversational ‘tone,’ and makes a fine way to spend evenings that have clouded over, or afternoons while waiting for the sun to go down... In the end Cosmic Challenge easily met (and exceeded) the expectations pre-publication excitement might have raised. As a result, my recommendation regarding the book is simple: if you don’t own a copy yet, go out and buy one." – Thomas Watson, Cloudy Night Telescope Reviews
"Phil Harrington is a well-known astronomy writer and has published a lot of material about deep sky observing. Cosmic Challenge is his latest and probably best work to date... All-in-all this is an excellent observing guide, with something for everyone whether you observe with your unaided eyes or you have a 20 inch light bucket. It’s both very readable and a proper observing guide suitable for use during an observing session. Highly recommended." - FJAstronomy.com