An achondrite is a type of stony meteorite that does not contain chondrules, which are small, round particles found in many other meteorites. Instead, achondrites are formed from differentiated parent bodies, meaning they have undergone processes that separate their materials based on density. This gives them a more complex mineral composition, often resembling terrestrial rocks. Achondrites are important for understanding the early solar system and the formation of planetary bodies. They are believed to originate from bodies like the Moon or Mars, providing insights into the geological history of these celestial objects. Their study helps scientists learn about the processes that shaped our solar system.