“These exoplanets are unlike anything in our solar system,” says lead author Harrison Allen-Sutter of ASU’s School of Earth and Space Exploration.

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

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.

First, they immersed silicon carbide in water and compressed the sample between diamonds to a very high pressure.

As they predicted, with high heat and pressure, the silicon carbide reacted with water and turned into diamonds and silica

Planetary scientists and astrobiologists are using sophisticated instruments in space and on Earth to find planets with the right properties and the right location around their stars where life could exist

While Earth is geologically active (an indicator habitability), the results of this study show that carbon-rich planets are too hard to be geologically active and this lack of geologic activity may make atmospheric composition uninhabitable