Final answer:
Neptune's discovery, Le Verrier's suggestion, and confirmation of gravitational theory.
Step-by-step explanation:
In September 1846, German astronomer Johann Galle became the first to observe the planet Neptune, which is named after the Roman god of the Sea. Neptune is about 30 times farther from the Sun than Earth and is larger than our planet. Sometimes, Neptune's orbit crosses that of Pluto.
The discovery of Neptune was a major triumph for gravitational theory and confirmed the generality of Newton's laws. It was suggested by Le Verrier to Johann Galle, who found and identified the planet based on Le Verrier's predictions in September 1846.
Overall, the sentence is mostly correct, with some minor punctuation adjustments needed.