Icy gems may be forming deep within Neptune and Uranus. In the depths of these gas giants, the pressures are so intense that the carbon present in the atmosphere condenses and forms small diamonds, which fall like rain in the depths of these incredible planets. The outer planets of our Solar System are difficult to study, however. Only a single space mission, Voyager 2, flew to reveal some of its secrets, so the diamond shower remained just a hypothesis.

In addition to the persistent mystery of the diamond shower, there is a great loss in our failure to study Uranus and Neptune inside and out. It limits our understanding of the Solar System and the galaxy, because planets this size have turned out to be extremely common in the Milky Way. The number of planets similar in size to Uranus and Neptune that have been found in the galaxy is approximately nine times greater than the number of much larger planets similar in size to Jupiter and Saturn. The outermost planets also appear to have scars that can tell us a lot about the formation of our Solar System. Therefore, there is a growing sense of urgency to explore Neptune and Uranus, both to better understand where and how planetary systems form, and also to refine our ideas about where to look for planets that could support life.

Right ad Although we have been limited by spacecraft and ground-based telescopes in how much we can learn about the exterior of Uranus and Neptune, advances in laboratory simulations are allowing remarkable new insights into what is happening inside their interiors, including the which gives rise to the rain of diamonds. . Discoveries like these reveal the complexity of the chemical processes involved in the evolution of these planets. Our simulations give clues about the inner nature of worlds far beyond the Solar System, even worlds we may never see directly from the outside.