Achondrites

Definition

Achondrites are a type of stony meteorite that lack the round, chondrule structures found in other meteorites. They are believed to originate from differentiated parent bodies, such as asteroids, which have undergone melting and separation into layers. This differentiation process is key in understanding the formation and evolution of planetary bodies within our solar system.

5 Must Know Facts For Your Next Test

1. Achondrites make up about 8% of all known meteorites and are primarily derived from the crusts of differentiated asteroids.
2. They can be classified into several groups, including howardites, eucrites, and diogenites, each originating from specific parent bodies in the asteroid belt.
3. Unlike chondrites, achondrites do not contain chondrules and instead have a more homogeneous texture due to their formation from melted materials.
4. The study of achondrites provides insight into the thermal evolution of their parent bodies and helps scientists understand processes such as core formation.
5. Some achondrites are linked to Mars, providing important clues about the planet's geological history and past environments.

Review Questions

• How do achondrites differ from chondrites in terms of structure and origin?
  • Achondrites differ from chondrites primarily in their structural composition; while achondrites lack chondrules, chondrites contain these spherical structures formed in the early solar system. Additionally, achondrites originate from differentiated parent bodies that have undergone melting and layering processes, whereas chondrites come from more primitive bodies that did not experience significant differentiation. This distinction highlights the evolutionary differences between these two types of meteorites.
• Discuss the role of achondrites in understanding planetary differentiation and the formation of celestial bodies.
  • Achondrites play a significant role in understanding planetary differentiation because they provide evidence of the processes that lead to the formation of distinct layers within planetary bodies. Their composition reflects the materials that were present in differentiated asteroids, offering insights into how these bodies evolved thermally and chemically. By studying achondrites, scientists can infer how different celestial bodies, including planets and moons, formed and changed over time.
• Evaluate the implications of studying Martian achondrites for our understanding of Mars's geological history.
  • Studying Martian achondrites has profound implications for our understanding of Mars's geological history as they contain valuable information about past volcanic activity and surface conditions. These meteorites provide direct samples of Martian crust material, allowing researchers to analyze mineralogy and isotopic compositions that reveal Mars's evolution over time. This research helps piece together Mars's potential for habitability and guides future exploration efforts to search for signs of past life on the planet.

Related terms

Chondrites:

Chondrites are stony meteorites that contain chondrules, which are spherical grains formed from molten droplets during the early solar system.

Planetary Differentiation: Planetary differentiation refers to the process by which a planet or asteroid separates into distinct layers based on density, leading to the formation of a core, mantle, and crust.

Parent Body: The parent body is the original celestial body from which meteorites are derived, often undergoing processes like melting and differentiation before breaking apart.