A team of researchers from Germany and the United States has succeeded in showing that “diamond showers” form in the ice giants of our solar system. The team has managed to simulate the conditions inside the cosmic giants, and for the first time, observe in real time the fission of the hydrocarbon, which causes the carbon to turn into pieces of diamond.
The interior of planets like Neptune or Uranus is made up of a solid core wrapped in thick layers of a kind of ice, which is mainly made up of hydrocarbons, water and ammonia . Astrophysicists have long been speculating that the extreme pressure of more than 10,000 kilometers below the surface of these planets splits the hydrocarbons causing the formation of diamonds, which then sink deeper into the planet’s interior. “Until now, no one has been able to directly observe this shower of diamonds in an experimental setting ,” according to Dr. Dominik Kraus, one of the study’s lead authors. “In our experiment, we exposed a special type of plastic: polystyrene, which also consists of a mixture of carbon and hydrogen , to conditions similar to those of Neptune or Uranus.”
How have scientists achieved this effect? Driving two shock waves , driven by an extremely powerful optical laser in combination with an X-ray source. Applying high pressure and temperatures of about five thousand degrees Celsius , they compressed the plastic. “The smaller and slower first wave is overtaken by a stronger second wave,” explains Kraus. ” Most diamonds form the moment when the two waves overlap .” And since this process takes only a fraction of a second, the researchers used ultra-fast X-ray diffraction to take snapshots of the creation of the diamonds and the chemical processes involved. “Our experiments show that almost all carbon atoms are compacted into nano-sized diamonds,” summarizes the researcher.
Based on these results, the study authors assume that the diamonds of Neptune and Uranus are much larger structures and likely sink into the planet’s core for thousands of years. “Our experiments also provide us with a better view of the structure of exoplanets,” anticipates Kraus.
Researchers can make two main measurements on these cosmic giants outside our solar system: the first is mass , based on positional changes of the parent star; and the other is its radius , derived from the shadow that is projected when the planet passes in front of a star. The relationship between these two measurements offers clues about the chemical composition of the planet , for example, whether it is made up of light or heavy elements.
Engineering application
But, in addition to astrophysical insights, these experiments also have potential for practical application. The nano-diamonds created in the experiments can be used in electronic instruments, medical procedures, or as cutting materials in industrial production. Laser-based production could mean a cleaner and more controllable process than has been used so far.
Referrals:
D. Kraus, J. Vorberger, A. Pak, NJ Hartley, LB Fletcher, S. Frydrych, E. Galtier, E J. Gamboa, DO Gericke, SH Glenzer, E. Granados, MJ MacDonald, AJ MacKinnon, EE McBride, I. Nam, P. Neumayer, M. Roth, AM Saunders, AK Schuster, P. Sun, T. van Driel, T. Döppner, RW Falcone: Formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions. Nature Astronomy, 2017 (DOI: 10.1038 / s41550-017-0219)
Image: Greg Stewart / SLAC National Accelerator Laboratory
