Close-up of a sample particle from asteroid Bennu. Credit: NASA/Scott Eckley A new study shows that, at an incredibly small scale, the building blocks inside the asteroid Bennu are not evenly mixed. Instead, organic material and minerals are grouped into three clearly different chemical regions. These findings help scientists understand how liquid water once changed the asteroid's composition over time. Bennu is known as a carbonaceous asteroid, meaning it is rich in carbon-based material,