Eos: “Uranus and Neptune should be Top Priority, says report”

Launching a small orbiter with an accompanying atmospheric probe to the solar system’s ice giants—Uranus and Neptune—should be a top priority for NASA in the coming decade, say planetary scientists who conducted a review of potential missions to do so. Beyond being scientifically valuable, such a mission to each planet is technologically feasible, the team said.

It is important that the next mission to an ice giant study the entire system: the planet itself, the atmosphere, the rings, the satellites, and the magnetosphere, Mark Hofstadter, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., told Eos. Hofstadter is a coauthor of the June 2017 report that reviewed the mission potential for Uranus and Neptune. Every component of an ice giant system challenges our understanding of planetary physics in a unique way, he said.

Kimberly M. S. Cartier

Hard not to agree with this assessment. Alongside the five key questions highlighted in the article, there are other important mysteries to investigate in each of those systems, related to their formation and the early history of the solar system, for example the tilt of Uranus’ orbit, most likely caused by a giant impact, and the origin of Triton, Neptune largest moon with an unusual, retrograde orbit. Even if both worlds are further out in the solar system, it feels like a huge missed opportunity to not have visited either of them for the past 30 years.

A Voyager 2 view of Neptune processed by an amateur image processor. The image was taken on August 31st 1989 around 17:00 UTC by Voyager 2’s narrow angle camera Source: NASA/JPL-Caltech/Kevin M. Gill

I would go even further and propose that there should be at any time at least a mission orbiting each of the four giant planets, like we managed with Mars for the past years. These are all complex systems that should be monitored for decades as they slowly make their way around the Sun. The missions could also double as platforms for deep-space observations, or to scan the outer solar system for distant, hidden bodies. Correlating data from several sources inside the solar system could make finding Kuiper Belt worlds or long period comets much easier by tracking their position against background stars.