Should I buy science books in Spanish?

Should I buy science books in Spanish?
 

I want to read a Spanish book about Earth history (natural history, like millions and billions of years ago), but I'm not sure if it's a good idea because such books are advanced and will be hard to read. I already own a book History of Life and it was challenging enough in English. I've also heard that you should try reading anything in Spanish that you find interesting.
What do you think?

Reading in Spanish will certainly be enriching. The "hard" words in English will most likely be cognates (or "friends") in Spanish, so you'll have no problem recognizing them. Just remember to use proper Spanish pronunciation when you encounter them. And that will be the least of your problems, because all words in Spanish follow strict pronunciation rules, unlike English.

Let's have a look at the word 'paleontology,' which is 'paleontología' in Spanish.

In American English, the phonetic pronunciation is /pey-lee-uhn-tol-uh-jee/.

In Spanish, the pronunciation is similar to /pah-ley-ohn-toh-loh-khee-ah/. Spanish pronunciation is simple. Its vowels are pure.
(The /kh/ in the pronunciation guide is the /ch/ found in Bach (the German composer), when said correctly by the host of a classical music radio station: /bahkh/.)

Reading about topics you already know does help when you're learning a foreign language.
My advice is that you start with popularization texts, which will be on topics you already know, but with a relatively easy use of language. Also, if you can find books you have read before in English, you'll find it easier to read in Spanish.
After you feel comfortable enough with those texts, you can start looking for more challenging specialized articles or books. :)

This is a common misconception. The real problem with any language are simple everyday things. It's very easy to underestimate the volume of that universe. If you enjoy reading, try novels. Just because they contain a lot of dialog. This means they contain a lot of human speech which is heart and soul of any language.