Short answers, pulled from the story.
Johann Gottfried Galle discovered Neptune on the 23rd of September 1846. This discovery occurred using a letter from Urbain Le Verrier and a recently drawn chart of the sky to locate the planet just northeast of Iota Aquarii.
Neptune has the fastest winds in the solar system, reaching speeds of 2,100 kilometers per hour. These winds blow in the opposite direction of the planet's rotation and create a chaotic environment despite the planet's calm appearance.
Scientists believe diamond rain occurs at depths of 7,000 kilometers within Neptune. At this depth, pressure and temperature decompose methane into diamond crystals that rain downwards through a layer of superionic water.
Triton will reach the Roche limit and be torn apart by Neptune's gravity in about 3.6 billion years. This event is caused by tidal acceleration that is slowly spiraling the moon inward toward the planet.
The Voyager 2 spacecraft flew by Neptune on the 25th of August 1989. It remains the only spacecraft to visit the planet and provides the primary data about Neptune's atmosphere, magnetic field, and moons.
Neptune completed its first full barycentric orbit since its discovery on the 11th of July 2011. The planet has an orbital period of 164.79 years, meaning it has completed only one full orbit since being found in 1846.