"Brendan Buckley's Universe and Everything In It" by Sundee T. Frazier

Brendan is into science. There are so many questions to find the answers to, and he keeps them all in his top secret notebook of scientific discovery. He is mastering the study of Tae Kwon Do, and is working on creating his own rock collection. Brendan is thrilled to meet Ed DeBose, who is a famous rock collector. He is even more excited when he learns that Ed is actually his long-lost grandpa! Brendan's parents don't want to talk about why Ed hasn't been part of the family. Can Brendan use his detective powers to solve the mystery?