Ice Giant or Magma Ocean World?

Uranus and Neptune&ndash;known as our system&rsquo;s ice giants&ndash;are our least explored planets. &ldquo;Ice giant&rdquo; is one structure that matches the limited measurements we have from these planets, but, as today&rsquo;s preprint study points out, it&rsquo;s not the only one . (Image credit: NASA ; research credit: E. Young et al. (preprint); via Gizmodo )