Uranus is the loneliest thing in the solar system. It hasn't had contact with anyone in over 30 years, since NASA's Voyager 2 spacecraft whizzed by it on 24 January 1986. Thankfully, some good folks at NASA and elsewhere are advocating for missions to Uranus and its Ice Giant companion, Neptune, which could take place at some point in the next few decades.
The team's 529-page-long report, released this month, elucidates the benefits of visiting these two woefully-understudied worlds. Neptune and Uranus, the so-called "ice giants", are different from Jupiter and Saturn (the "gas giants"), in the sense that their mass is roughly 65 per cent water and other ices, such as methane and ammonia. Despite knowing so little about ice giants, the scientists behind the new mission study suggest these planets are incredibly common in our galaxy. A mission to either Neptune or Uranus could help us better understand exoplanets we haven't found yet.
Did we mention that Uranus and Neptune might be hiding vast oceans beneath their clouds? Because that seems like something worth looking into.
"Both Uranus and Neptune challenge our understanding of how planets form and evolve," Dr Curt Niebur, program scientist at NASA headquarters, told Gizmodo. "There are certain things about them which we cannot explain, [such as] their composition, how their magnetic fields are generated, and what geologic processes are active on their moons today."
Lovely, lopsided Uranus. (Image: NASA)
This latest report from NASA outlines myriad potential mission designs, including, yes, a probe into Uranus. The team is particularly keen on sending both a probe — which would plunge into the planet's atmosphere — and an orbiter that would hang out for several years, to at least one of the ice giants.
"A probe is the only way to measure heavy noble gases, isotopic ratios, and the bulk abundance of certain species," the researchers wrote. "An orbiter is required to give us vantage points and enough time in the system to understand variable phenomena (e.g., magnetospheric responses to the varying solar wind or weather variations), to allow us to encounter several moons, and to observe all components of the system under varying geometries."
Voyager 2 showed us so much about the ice giants that was previously unknown. It illuminated Neptune's rings; a giant, ephemeral vortex called the "Great Dark Spot"; and geysers on its largest moon, Triton. The spacecraft also found 10 of Uranus's 27 known moons, two new rings, and the planet's lopsided magnetic field. Still, there's so much left to learn about these weird worlds, such as what their interiors look like and what could have caused Uranus to have such an extreme spin axis that it basically rotates on its side. Maybe it's just been really drunk all these years.
The ice giant report will be considered as part of NASA's Planetary Science Decadal Survey, which outlines the agency's priorities for the next 10 years — in this case, from 2022-2032. The next report will likely be published sometime in 2018.
Until then, we wish the ice giants our best.
"Our understanding of how planets work is incomplete," Neibur told Gizmodo. "So studying Uranus and Neptune will help us understand how our solar system formed and how planets — including ones around other stars — evolve."