The spacecraft detected dark spots on Neptune's surface, which were later found to be massive storms in the planet's atmosphere. These storms produced intense winds and heavy rain in the form of methane droplets.
The storms were much larger and more powerful than any seen on Earth. The ship sustained damage forcing our crew to make an emergency landing on Neptune. Once the storm had passed the crew had minutes to conduct data collection and escape the next storm.
Among the samples collected was hail with a molecular resemblance to diamond crystals. They concluded that as the methane droplets fell through the atmosphere, they encountered layers where the pressure and temperature were just right for diamond formation, causing the carbon atoms to bond together and create tiny diamond crystals.
Members of the crew later launched a collection of diamonds from Neptune, called Neptune’s Collection, as a reminder of the mission and to share with the world.