Complex sentence: Entering the stratosphere, they find that the machine is the sole core of a giant meatball-a "meat" eroid-and that it is aware of the heroes so it sends sentient food to attack them (starting with a pizza).
Split into simpler sentences: Entering the stratosphere, they find that the machine is the sole core of a giant meatball-a "meat" ior-and that it is aware of the heroes. Then, it sends sentient food to attack them (starting with a pizza).