Uranus and Neptune could be full of rocks, new study suggests

Could Uranus and Neptune be full of rocks? One new study thinks so. Uranus and Neptune are two planets that have historically been classified and thought of as "ice giants," orbiting far out in the freezing edges of our solar system . But it's possible that our understanding of these planets' makeup could be totally off, and their atmospheres could be full of rocks, researchers suggest in a new study. "We found out that both Uranus and Neptune have their outer shells made mostly of rocks (and hydrogen and helium gas)," study author Yamila Miguel of the Netherlands Institute for Space Research told Space.com. This "goes against the common belief that they are ice-giant planets." These two planets both have inner rocky cores surrounded by icy mantles enveloped by a thick atmosphere that has been thought to contain hydrogen, helium and methane gases as well as silicate clouds. In some high pressure areas, the gaseous atmosphere becomes fluid — but the results of this study suggest these atmospheres could also be littered with rocks. This research team was inspired to take a closer look at Neptune and Uranus thanks to recent research which has suggested that objects in the trans-Neptunian region, an icy region beyond Neptune, are more rocky than icy. Previous studies have suggested objects like Pluto , comets , and Kuiper belt bodies indeed have rocky atmospheres, the new study's researchers explained. …