NASA / UPROXX
Both Neptune and Uranus have magnetic fields which aren’t yet fully understood. Uranus as a whole has a magnetic axis which is about 60 degrees off its spin axis, suggested that perhaps Uranus was pounded by something huge. Yep. There’s so much we don’t yet know about Uranus, and also about Neptune, we guess, but we’re more interested in Uranus.
We’re learning a little bit more about Uranus (and Neptune) thanks to research published by Proceedings of the National Academy of Sciences and conducted by Alexander Goncharov of the Carnegie Institute; Richard Gaal and Philippe Gillet of the Ecole Polytechnique Federale de Lausanne; and Zamaan Raza, Adriaan-Alexander Ludl, Stefan Klotz, and Antonino Marco Saitta of the Université Pierre et Marie Curie. That’s a lot of names, but Uranus (and Neptune) can handle being septuple-teamed. That’s just what we’ve heard.
Their research found a potential explanation for the magnetic fields of Neptune and Uranus, and it boils down to salt and water. Ice at regular Earth pressure has at least 16 different crystalline patterns, but most of these patterns wouldn’t occur under higher pressure. At 20,000 times of Earth’s pressure, only two types of ice can form (ice VII and ice VIII). At 600,000 times Earth’s pressure — the type of pressure inside a planet with an ice-core, for example (Uranus is filled with ice, we’ve heard) — those two types of ice transform into another type, called ice X. It’s also known as non-molecular ice because the water molecules break apart.
The team theorized this type of ice might be able to conduct electricity under certain conditions, and that’s where the salt comes in. When two types of salt (regular table salt and lithium chloride) were added to ice VII, the researchers found that ice X could be formed at higher pressures than expected. Meaning Uranus and Neptune may indeed have salty, icy cores which can conduct electricity, thus explaining why Uranus is so magnetic. (And also Neptune, we suppose.) It wouldn’t have been surprising for NaCl and LiCl to be present when Neptune and Uranus were formed.
Uranus is so fascinating. And also Neptune, we suppose.
(Via Carnegie Science Spring 2016 issue, page 7)