Could entire planets be made of diamonds? Scientists think so

Some planets may be made almost entirely of diamonds—imagine worlds glittering beneath their crusts!

Key Takeaways

1. Scientists confirmed the possibility of diamond-rich planets using lab simulations of extreme conditions.
2. These “diamond planets” could exist in the trillions across the vastness of the universe.
3. Diamond planets form near stars with high carbon-to-oxygen ratios, unlike our Sun.
4. Harsh, inhospitable atmospheres make these planets unlikely to support life.
5. Lab experiments revealed that silicon carbide converts into diamonds under intense heat, pressure, and water.

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The Formation of Diamond Planets

Diamonds may be rare and precious on Earth, but across the universe, entire planets might be composed primarily of the sparkling gem. Recent research, published in The Planetary Science Journal, suggests that exoplanets rich in carbon could contain vast quantities of diamonds beneath their surfaces, making them unlike anything in our solar system.

Scientists from Arizona State University and the University of Chicago conducted lab experiments to test the plausibility of diamond planets. These experiments simulated the extreme heat and pressure conditions found on carbon-rich planets. By submerging silicon carbide—a molecule of silicon and carbon—in water, compressing it with a diamond-anvil cell, and applying laser heat, the team successfully created diamonds and silica.

The findings confirm that such planets could indeed exist under the right conditions. The key ingredients include a high carbon-to-oxygen ratio, the presence of water, and immense pressure.

Trillions of Glittering Worlds

The vast scale of the universe makes the existence of diamond planets statistically likely. Harrison Allen-Sutter, the study’s lead author, pointed out that even if only one in a billion planets are diamond-rich, the sheer number of galaxies and planets in the universe could mean trillions of these sparkling worlds.

These planets, known as carbide exoplanets, form in star systems with carbon-rich environments. Unlike Earth’s oxygen-dominated planetary chemistry, these worlds contain molten silicon carbide near their cores. When exposed to extreme conditions, this compound can transform into diamonds and silica.

Inhospitable Yet Intriguing

Despite their dazzling interiors, diamond planets are unlikely candidates for life. Their atmospheres, rich in methane and low in oxygen, create harsh conditions. Additionally, their extreme hardness would prevent geological activity, a process crucial for stabilizing planetary temperatures and supporting life.

These planets are theorized to exist near stars with a high carbon-to-oxygen ratio—a condition absent in our solar system. This means that diamond planets are entirely alien in nature, offering a glimpse into the diversity of planetary compositions across the cosmos.

While these worlds might not support life, they provide valuable insight into planetary formation and the chemical processes that shape distant exoplanets. The discovery of diamond planets adds another fascinating layer to our understanding of the universe’s complexity.