Overview

• Dark comets combine characteristics of both asteroids and comets, lacking a coma but showing sublimation jets.
• Researchers estimate between 0.5% and 60% of near-Earth objects could be dark comets.
• These objects likely originate from the inner asteroid belt, indicating more ice in that region than previously thought.
• Dark comets' nongravitational accelerations suggest they contain subsurface ice.
• The study raises new questions about the origins of Earth's water and the dynamics of the inner solar system.