We don't fully know the exact size of outer space, but it's estimated at around 28 billion light-years. That's enormous! Outer space is a result of numerous instances of cause and effect, because every celestial event from shooting stars to meteoroids play a role in a bigger, ongoing process. Readers explore the many events within outer space that each impact another event, as they read about different processes that they may not even realize are happening above their heads. Charming illustrations guide them to understanding more about this topic, which helps them to grasp STEM concepts from outside of the classroom.