It's Raining Diamonds!

According to US scientists, the planets in Earth’s solar system contain extreme atmospheric conditions that account for unique weather patterns; high winds, enormous storms, and of course… diamond rain.

by Jamie Hirano on August 2020

Storms are often the culprit when it comes to destruction and devastation on Earth, with the largest recorded hurricanes and tornadoes wiping out entire cities in their wake. Hurricane Katrina’s appearance in August 2005 was one of the deadliest storms to hit the United States, leaving thousands dead and millions homeless. Humans have learned to expect the negative effects of these disturbances. However, scientists have discovered how extreme weather cases on other planets in the solar system (the eight planets and their moons which orbit the sun) can lead to valuable results. Now consider this: what if lightning storms could create diamond rain? On planets Jupiter, Saturn, Uranus, and Neptune, a diamond in the rough might first start with its tempests (a violently windy storm). 

So what is diamond rain?

It is excitingly exactly what it sounds like; diamonds as large as a centimeter across raining, or rather hailing, down on planets. An experiment conducted in 2017 which simulated (copy the appearance of) the deep interior of ice giant Neptune, supported the hypothesis that it rains diamonds on the planet. However, Neptune is not the only planet with beautiful gems in the sky. Evidence points towards other giants Jupiter, Saturn, and Uranus as well. However, before diving into the details of how diamond rain occurs, a summary of the eight planets in the solar system and their properties will help us to further understand these planets.

First, there are the four planets closest to the sun, Mercury, Venus, Earth, and Mars. They are called terrestrial planets because they are composed of mainly rock or metals. Their proximity (closeness in space) to the sun leads them to have hotter temperatures than Jupiter, Saturn, Uranus, and Neptune. All of the properties of each planet are credited to the sun. Imagine cooking smores by a campfire. As the marshmallow gets closer to the fire, it melts faster as the temperatures are hotter by the flames. This is much like each planet’s relationship with the sun.

The inner planets are one of the two different groups that the solar system’s planets fall under. The properties (special qualities relating to one thing) of the second group of outer planets, Jupiter, Saturn, Uranus, and Neptune, are what influence diamond rain to fall. These influences are also what makes the outer planets inhabitable, meaning that humans would never be able to live on them. 

Next are the outer planets, also known as “giants”. Jupiter, Saturn, Uranus, and Neptune are all classified as giants for their lack of surfaces. If an aircraft were to attempt to land on any of these giant balls of gas and ice, it would experience an increase in temperatures and pressure while sinking to their rocky cores. In comparison to the terrestrial planets closer to the sun, such as Mercury, Venus, Earth, and Mars, these giants are significantly larger. This is how they got their name. Neptune is the smallest of the giants, but it is still four times wider than Earth. If Earth were the size of a nickel, Neptune would be as big as a baseball!       

Giants of the Solar System

Jupiter and Saturn are the largest planets in the solar system. This is no mistake; at the early development of the solar system’s suns and planets, the outer temperatures of the solar system were much colder. Due to the lack of heat, the giants were left with elements that would not vaporize (turn into a gas). These elements were water and methane, and from there they attracted large amounts of hydrogen and helium. The hydrogen and helium gas causes their large size, and are what also make-up stars. Jupiter and Saturn are sometimes referred to as failed stars because they do not have the required mass that stars need to develop. A stars’ large mass houses the internal pressures and temperatures necessary to fuse hydrogen to helium. This result powers each star as their primary (main) energy source.   

Of the eight planets in Earth’s solar system, Uranus and Neptune orbit (an object’s circular path around another) the furthest away from the sun. As the sun is the solar system’s main source of heat, the blue planets’ distance gives rise to extreme climate and weather. Neptune is the farthest away from the sun at a distance of 2.7815 billion miles, so its heat source comes from its core. Think back to the marshmallow analogy mentioned earlier. Imagine that the coldest areas farthest away from the campfire are the outer layers of Neptune. The heart of the fire would then represent the planet’s core. Neptune’s mass internal heat source causes it to radiate (give off energy in the form of waves) more than twice as much energy as it receives. The estimated core temperature of Neptune is 7273K, 1873K more than Earth’s core temperature of 5400K.

Nicknamed the “ice giants”, they are known for the water, methane, and ammonia that surround their rocky centers. This icy layer of elements can be found in the mantle of both Uranus and Neptune (as shown in the image above). The mantle is the bulk or majority of the inside of a planet. The distinguishing feature for ice giants came from the deep extension of their mantles. While these planets share primary atmospheric components of hydrogen and helium like “gas giants” Jupiter and Saturn, the methane in Uranus and Neptune’s atmospheres sets them apart. This methane gas accounts for the blue-ish hue that these ice giants showcase. Due to methane’s absorption of red light, blue light is left to reflect outwards.   

The Breakdown: How Diamond Rain Forms

Diamonds typically form through intense heat and pressure crystalizing carbon atoms into the precious gems. Jupiter, Saturn, Uranus, and Neptune follow a similar process.

Saturn and Jupiter contain large amounts of carbon in their atmospheres. Their lightning storms hit carbon soot, which hardens it into graphite. As it falls downward, the pressure of the atmosphere hardens it further until it becomes a diamond. On Neptune and Uranus, diamond storms are formed through their hydrocarbons, which experience high pressures and temperatures as they fall from the sky deeper into the planets’ core, where they eventually transform into diamonds. With all of this pressure pushing down on the diamonds, their fall downwards mimics that of raindrops on Earth.

Despite the many advances in science and technology that society currently accomplishes, there is still a lot of unknown information on the solar system. This is especially the case with ice giants Uranus and Neptune, which are one to two billion miles away from Earth. While scientists find themselves conducting educated guesses rather than facts on the unique characteristics of each planet, their findings have proved that diamond rain most likely occurs. When space crafts do manage to get closer to these ice giants, they might just prove this fascinating diamond rain hypothesis to be true.