Definition
A C-type asteroid is a category of asteroids whose composition is dominated by carbon minerals, hydrated silicates, and sometimes organic compounds. Their surface appears dark due to low reflectivity.
Composition
These asteroids contain altered silicates, phyllosilicates, carbon in various forms, as well as traces of ice and complex organic substances. Their weakly differentiated nature preserves elements close to those of the original solar nebula.
Internal Structure
The structure is heterogeneous, with a porous crust covering layers mixing primitive rocks and carbon compounds. Their relatively low density suggests a not very compact interior, sometimes similar to an aggregate.
Function and Role in the Solar System
These asteroids play a fundamental role in understanding the origin of planets, as they preserve little-altered materials. Their presence in the main belt and sometimes further out provides clues about the distribution of organic substances.
Evolution
They undergo few internal transformations, but their surface is modified by impacts, space weathering, and interactions with solar radiation. Some fragments are the source of carbonaceous meteorites that reach Earth.
Limitations
Their study remains limited due to the difficulty of observing dark surfaces and collecting samples. However, recent space missions allow more direct data on their nature to be obtained.