Researchers have discovered signs that the cores of Neptune and Uranus might be occupied by 'exotic' molecular compounds, and they seem to only stick around under massive pressure. Between the compounds that are possible to exist inside Neptune, Uranus, and Jupiter's frozen moon, Europa, where carbonic acid (H2CO3) and a tremendously uncommon compound of molecular hydrogen and methane (2CH4:3H2).
Artem Oganov, a member of the team, from the Moscow Institute of Physics and Technology in Russia, said, "The smaller gas giants Uranus and Neptune consist of a large amount of hydrogen, carbon, and oxygen. We have discovered that at a pressure of some million atmospheres, unpredictable compounds should form in their cores. The cores of these gas giants may largely consist of these exotic molecular compounds."
To discover the compounds, scientists used a powerful algorithm named the Universal Structure Predictor: Evolutionary Xtallography (USPEX), which can calculate how compounds and crystals will form in different pressures. They decided to test with carbon-hydrogen-oxygen systems in precise, because these three compounds are used to create organic matter and, hence, are common among gas giants and in new types of planets.
Oganov said, "This is a significantly important system, because all organic chemistry 'rests on' these three components, and until now it had not been completely clear how they act under thrilling pressures and temperatures. In addition, they play a vital role in the chemistry of these gas giant."
They discovered that at very high pressures, these three components formed are extremely rare compounds. For example, at approximately 4 giga-pascals, about 40,788 kg per square centimeter (580,151 pounds per square inch), methane and molecular hydrogen come together to form something known as co-crystals. Co-crystals are so rare; chemists cannot even approve a definition for them. At about 6 giga-pascals in the simulation, varieties of co-crystal made from water and methane, called hydrates, were capable of forming. At .95 giga-pascals, carbonic acid became stable. This is a pretty huge deal because carbonic acid is extremely unstable below ordinary conditions, requiring vacuum and at very low temperatures to be present as a clean compound at all.
Oganov said,"It is promising that the cores of Neptune and Uranus may contain important amounts of a polymer of carbonic acid and ortho-carbonic acid."
Also discovering the exotic compounds, the scientists took notes on how the carbon-hydrogen-oxygen systems improved all the way up to pressures of 4 hundred giga-pascals. Doing so has permitted them to watch as the elements moved around, creating and stabilizing into different compounds, which in the end produced about 125,000 different chemical structures for study. However all of this sounds pretty crazy if you are not well experienced in chemistry, the takeaway is that we are now on the end of understanding how compounds that are uncommon here on Earth might be usual inside the extremely pressurized cores of gas giant planets.
And knowing this, researchers might be capable of understanding more about how these gas giants formed, and what takes place inside them. Of course, until the reports can be confirmed in something other than a computer model, we cannot say for certain if the team's calculations are accurate, but with Jupiter hurling out some pretty massive surprises this week, we would not put any strangeness past our planetary neighbors.