Scientists have wondered for decades what goes on below the beautiful clouds of Jupiter. Some suggest that it actually rains Helium deep inside the gas giant! The existence of helium rain inside Jupiter was first hypothesised 40 years ago. But, it was not possible to achieve the experimental conditions required to prove the hypothesis. Now, physicists finally produce the interior conditions of the planet here on Earth!
Marius Millot, a physicist at Lawrence Livermore National Laboratory (LLNL) said,”We discovered that helium rain is real and can occur both in Jupiter and Saturn. This is important to help planetary scientists decipher how these planets formed and evolved”.
Millot and his colleagues put a mixture of Helium and Hydrogen in between two diamonds. They compressed the mixture to a mindboggling pressure of 60-180 gigapascal (1 GPa = 40,000 times Earth atmosphere pressure) by hitting the concoction with a powerful laser. As the pressure and temperature increased and the material started to become more reflective. This suggested that the helium was separating from the hydrogen as helium becomes liquid metal under these conditions. But, at even higher pressure and temperature, the reflectivity decreased, showing that the helium and hydrogen were mixing back again.
At pressure and temperature deep within Jupiter, hydrogen and helium don’t mix and exist separately. Helium droplets form and are more dense than hydrogen, causing them to “rain” down. Physicists estimated that hydrogen and helium will stay separate at a depth of 11,000 kilometres to 22,000 kilometres.