In the universe, the sky of ice giants may be full of diamonds. Compressed carbon compounds can turn into diamonds at temperatures that researchers did not expect, which may make "diamond rain" a common phenomenon on ice giants. The relevant research was published in Nature-Astronomy on January 8.
In the past, laboratory experiments have confused people about the conditions for the formation of diamonds inside ice giants such as Uranus and Neptune. There are two types of experiments used to study this problem: one is a dynamic compression experiment, that is, the carbon compound is suddenly impacted; the other is a static compression experiment, that is, the carbon compound is gradually compressed in a chamber. So far, dynamic compression experiments require higher temperatures and greater pressure to form diamonds.
Mungo Frost and colleagues of the SLAC National Accelerator Laboratory in the United States conducted a new set of experiments using static compression and dynamic heating. They squeezed polystyrene between the two diamonds and achieved compression by bombarding the former with X-ray light pulses.
Researchers have observed that polystyrene begins to form diamonds at a temperature of about 2200℃ and a pressure of 19 gipar, which is similar to the shallow interior of Uranus and Neptune.
This pressure is much less than the pressure required by earlier dynamic compression experiments to form diamonds, and the reaction time is longer than the usual dynamic compression experiments, which may explain why such experiments do not form low-pressure diamonds.
Frost said, "It is inconsistent with the established results, and it is not what we expect to see, but it connects everything. It turns out that this is all caused by different time scales.
This discovery may mean that there may also be "diamond rain" on planets smaller than we previously thought. According to the researchers' calculations, more than 1,900 of the confirmed exoplanets may have "diamond rain".
This also shows that in the solar system, the depth of diamond formation may be shallower than we thought, which may change our understanding of the internal dynamics of giant planets. This shallow formation may cause the "diamond rain" to pass through a layer of ice in the process of sinking to the centre of the planet, which in turn will affect the magnetic field of the planet, which is complex and little is known about.
Relevant paper information:https://doi.org/10.1038/s41550-023-02147-x
Source: China Science News