Work on the decadal survey will begin next year and will likely be finished sometime in 2021 or 2022. The report will help inform NASA’s next planetary science decadal survey, which determines the agency’s exploration priorities for the coming decade. In 2017, he coauthored a report that detailed various mission proposals to Neptune and Uranus. Hofstadter has hope that a return mission to Neptune is feasible in the next decade. “Yet they are everywhere we look in our galaxy, so learning some of these fundamental things is really going to advance our big-picture understanding of how planets form and evolve.” “Right now we're in a situation where we recognize that these ice giants are kind of weird, but we don't understand what they're made of, how they're put together, or why they even exist,” Hofstadter says. In addition to Triton, Voyager 2 also found six other moons and four lumpy rings circling the planet. This suggested it was tectonically active and perhaps host to a vast subsurface ocean. Voyager also got a good look at Triton, Neptune’s largest moon, and saw geysers erupting from its surface. At the time, the planet was host to the Great Dark Spot, an Earth-sized storm that has since disappeared.

What they found was a planet covered in dense, methane-rich clouds that whipped around Neptune at more than 1,000 miles per hour, making it the windiest spot in the solar system. “The level of excitement is the highest I’ve ever seen here.”īefore Voyager 2 made its pass just 3,000 miles above Neptune's atmosphere on August 25, 1989, scientists knew next to nothing about the place. “We are looking at the frontier of the solar system, the last planet,” Sagan told a CNN television crew that had assembled for the occasion. It was the first-and so far only-spacecraft to visit the mysterious blue ice giant lurking at the edge of the solar system. The Voyager 2 spacecraft had just completed its decade-long mission by making its closest pass to Neptune, before continuing on into interstellar space. It was just after midnight at mission control center at NASA’s Jet Propulsion Laboratory, and Carl Sagan was exuberant.

Neptunes missions