Complex sentence: After clearing up a misunderstanding, the Tritovores explain that they were making a routine goods collection with San Helios before they crashed, and reveal that only a year earlier the planet had had a hundred billion inhabitants and a thriving ecosystem.
Split into simpler sentences: After clearing up a misunderstanding, the Tritovores explain that they were making a routine goods collection with the planet they are now on, San Helios, when they crashed. They also reveal that only a year earlier San Helios had housed a hundred billion inhabitants and a thriving ecosystem.