Research: Diamond rain falls over many planets

If it is ever possible to fly through the extreme conditions of Neptune's atmosphere, we could experience the fascinating phenomenon of diamond rain.

According to a new study by an international team of researchers, such a "glowing blizzard" may be relatively common in the universe.

Carbon can bond into a crystal on giant, icy gas planets like Neptune and Uranus because of the extremely high temperatures and pressures deep in the atmosphere. These conditions break down hydrocarbons such as methane, allowing the carbon atoms in them to bond with four others and form hard diamond particles.

Based on the experiments described in the latest study, in which diamond formation processes were simulated in laboratory conditions, the temperature and pressure thresholds for this type of diamond formation are lower than scientists had thought.

This would make it possible for a diamond shower to form on smaller gas planets, so-called "mini-Neptunes". There are many such planets outside the solar system that we know of.

These findings could also explain some mysteries related to the magnetic fields of Uranus and Neptune.

"This ground-breaking discovery not only deepens our knowledge of icy planets, but also has implications for understanding similar processes in exoplanets outside the Solar System," said physicist Siegfried Glenzer of the SLAC National Accelerator Laboratory in California, Science Alert reported.

The team behind the new study used Europe's XFEL (X-Ray Free-Electron Laser) to observe the diamonds formed with polystyrene foil from a hydrocarbon compound.

This configuration allowed the team to observe the process longer than was possible in previous experiments. This ongoing research has shown that although intense pressure and ultra-high temperatures are still required, they may not need to be as extreme as previously thought.

In terms of planets, this suggests that diamonds could form at a shallower depth than scientists thought, and that would mean that descending diamond particles, entraining gas and ice, could affect magnetic fields of these planets in a more direct way than we have hitherto understood.

Unlike Earth, icy planets such as Neptune and Uranus do not have symmetrical magnetic fields. Until now, it's been something of a mystery — magnetic fields weren't thought to form in the planet's core — and diamonds could help explain it.

"It is possible that they cause movements in the conducting ices found on these planets and influence the generation of their magnetic fields," explained physicist Mungo Frost.

All of this is intriguing, and future research can look into it in more depth. In recent years, scientists have come closer to understanding how this process might play out on distant planets and what its consequences might be.

Who knows—maybe one day we'll be able to do an actual field study in the atmospheres of Neptune and Uranus that will allow us to see firsthand how this diamond rain forms.

"Diamond rain on icy planets presents an intriguing puzzle to solve," Frost emphasized./BGNES