Carbon-rich exoplanets can be made up of diamonds and silica, according to a new study published recently in The Planetary Science Journal .

The study was conducted by a team of researchers from Arizona State University (ASU) and the University of Chicago.

According to the research, given the right circumstance, certain carbon-rich exoplanets can be made up of diamonds and silica.

"These exoplanets are unlike anything in our solar system," said lead author Harrison Allen-Sutter of ASU's School of Earth and Space Exploration.

Stars and planets are formed from the same cloud of gas, so their bulk compositions are similar. Entities with a lower carbon to oxygen ratio such as Earth are made of silicates and oxides with very less diamond content.

However, “exoplanets around stars with a higher carbon to oxygen ratio than our sun are more likely to be carbon-rich.”

Hypothesis

Researchers thus hypothesized that “these carbon-rich exoplanets could convert to diamond and silicate, if water (which is abundant in the universe) were present, creating a diamond-rich composition.”

“To test this hypothesis, the research team needed to mimic the interior of carbide exoplanets using high heat and high pressure. To do so, they used high-pressure diamond-anvil cells at co-author Shim's Lab for Earth and Planetary Materials,” explained an official release.

Researchers immersed silicon carbide in water and compressed the sample between diamonds to very high pressure. They then conducted laser heating and took measurements of the laser-heated sample at high pressures to monitor the reaction between silicon carbide and water. At high pressure, the silicon carbide reacted with water and turned into diamonds and silica supporting the hypothesis.

"Regardless of habitability, this is one additional step in helping us understand and characterize our ever- increasing and improving observations of exoplanets," said Allen-Sutter. "The more we learn, the better we'll be able to interpret new data from upcoming future missions like the James Webb Space Telescope and the Nancy Grace Roman Space Telescope to understand the worlds beyond on our own solar system."

Related Topics