Stowaway by John David Anderson

When scientists discover a rare and mysterious mineral buried in the Earth’s crust, they have no idea that it just happens to be the most valuable substance in the entire universe. It’s not long before aliens show up to our little corner of the galaxy offering a promise of protection, some fabulous new technology, and entry into their intergalactic coalition—all in exchange for this precious resource. A material so precious that other alien forces are willing to start a war over it. A war that soon makes its way to Earth.

Leo knows this all too well. His father, a Coalition scientist, decides it would be best for them to leave Earth behind. It’s on this expedition… Read more.