Simplify the following text for a Grade 6 native English-speaking person.
Original: Water vapor jets have been observed near the south pole of Saturn 's moon Enceladus , while nitrogen eruptions have been observed on Neptune 's moon Triton .
Simplified: Water vapor streams have been seen near the south pole of Saturn 's moon Enceladus . Nitrogen eruptions have been seen on Neptune 's moon Triton .