One of the most unusual things about Uranus and Neptune is their magnetic fields. Each of these planets has a hot, diffuse magnetosphere that is regular and wildly tilted from its spin axis like no other planet. It’s not entirely clear why, but thanks to a team of researchers, we may have a new piece of the puzzle: a truly strange, ionized form of water called aquadium, which can exist deep in the ultra-high pressure inside these strange, icy worlds. .

Aquadium consists of a normal water molecule with two extra protons, giving it a net positive charge that – in sufficient quantities – can create a planetary magnetic field similar to that of Uranus and Neptune. Planetary magnetic fields extend into space around the planets that create them. However, they are produced by moving charges deep within the planet, although the exact mechanism varies.

On Earth, it is an iron-nickel alloy that twists, rotates, convects and conducts electricity around the core, converting all kinetic energy into electron streams in what is called a dynamo. For Jupiter and Saturn, scientists believe metallic hydrogen is the conduit that allows electron flow.

Earth, Jupiter, and Saturn have relatively uniform magnetic fields that resemble the fields of a giant bar magnet moving along the planet’s rotation axis; field lines clearly connect the north and south poles, like a lattice. The magnetic poles of Uranus and Neptune are inclined 59 and 47 degrees from their rotation axes, respectively, and their magnetic field lines are constantly changing and shifting. And they’re not actually concentrated in the cores of the planets.

One possible explanation is that magnetic fields can be created by an ionically conductive liquid in which ions are charge carriers, rather than the liquid acting as a conductor for electrons. The question is; Which ions? Some, such as ammonium, are obvious possibilities. So could water molecules on planets play a more important role in this process?

The research team, led by physicist Jingu Hou of Nankai University in China, went back to the original principles along with models of how molecules evolve by delving into a concept called chemical hybridization.

This is the mixing or combining of orbital elements of an atom to form an atom that can bond in a new way. There are different types of hybridization, but sp3 hybridization is important here, where four orbitals form a tetrahedral structure around a central core.

At each of the four points of the tetrahedron there is either a single electron that can bond with another atom or a pair of electrons that cannot form bonds with other atoms. Oxygen has two single electrons and two electron pairs in its outer shell. If you bond a hydrogen atom to each of the available valence electrons, you get H.₂It – water.

Sometimes hydrogen without an electron (also known as an ex-proton) bonds itself to one of the electron pairs, forming a molecule called a hydronium ion.

“The question was: Can you add another proton to the hydronium ion to fill in the missing piece? Such a configuration is extremely energetically unfavorable under normal conditions, but our calculations show that there are two things that can make this happen,” says the physicist. Xiao Dong from Nankai University.

“First, very high pressure causes the volume of matter to shrink, and sharing a previously unused electron pair, oxygen, with a hydrogen ion (proton) is a great way to do this: the Po pair as a covalent bond with hydrogen (excluding both electrons); Second, you need a lot of protons, and that means an acidic environment, because that’s what acids do; they donate protons.”

Researchers ran computer simulations and this is what happened in conditions similar to those believed to exist on Uranus and Neptune. At a temperature of about 3,000 degrees Celsius (5,430 Fahrenheit) and a pressure of 1.5 million atmospheres, protons combine with hydronium to form H.₄HE₂ – aquarium.

Of course, this is still at a theoretical level. Further investigation of this possibility will require more detailed observations of the two most distant planets; But the discoveries give us a new way to understand blue freaks like Uranus and Neptune. They also have implications for chemistry more generally, the researchers write; “an important contribution to traditional physical and chemical theories such as the valence shell electron pair repulsion model, proton transfer and acid-base theory”.