Topic: Space

Scientists studied a sample from asteroid Bennu and found that its building blocks are not evenly mixed. Instead, they're grouped into three different chemical regions.

A team of scientists analyzed a sample from the asteroid Bennu and made an exciting discovery. They found that the building blocks inside Bennu are not evenly mixed. Instead, organic material and minerals are grouped into three clearly different chemical regions.

Bennu is a carbonaceous asteroid, which means it's rich in carbon-based material, including organic compounds. These compounds are important because they're similar to the chemical ingredients needed for life.

The sample was collected by NASA's OSIRIS-REx spacecraft and returned to Earth in September 2023. The scientists used advanced techniques called nanoscale infrared spectroscopy and Raman spectroscopy to study the sample. These methods allow them to identify chemical compounds by measuring how they interact with light.

The researchers found that Bennu's internal chemistry is not uniform. Instead, the material forms three repeating types of organic-mineral regions, each with its own distinct composition.

One type contains high amounts of aliphatic organic compounds, which are simple carbon-based molecules made of chains of carbon and hydrogen. Another region is rich in carbonate minerals, which often form in the presence of water and can provide clues about past watery environments. The third region contains organic compounds that include nitrogen, an element that plays a key role in biological molecules such as amino acids.

These differences show that Bennu's chemistry varies significantly from place to place, even at extremely small scales.

Water's uneven impact on Bennu suggests that liquid water likely interacted with different parts of the asteroid under varying conditions, creating a patchwork of chemical environments. This process is known as nanoscale heterogeneity.

Despite this history of water interaction, the researchers found that fragile organic molecules were still preserved. This is an important discovery because it shows that key chemical ingredients can survive even when exposed to water-related changes.

Why It Matters

Understanding Bennu's chemistry helps scientists learn about how life emerged on Earth and how liquid water interacted with asteroids in the early Solar System. This knowledge can also help us better understand our own planet's history and the possibility of finding life elsewhere in the universe.

Key Facts

• Bennu is a carbonaceous asteroid that orbits relatively close to Earth.
• The OSIRIS-REx spacecraft collected a sample from Bennu and returned it to Earth in September 2023.
• Scientists used nanoscale infrared spectroscopy and Raman spectroscopy to study the sample.
• Bennu's internal chemistry is not uniform, but instead forms three repeating types of organic-mineral regions.
• Water likely interacted with different parts of Bennu under varying conditions, creating a patchwork of chemical environments.

Key Terms

Carbonaceous asteroid

A type of asteroid that is rich in carbon-based material

Implications

Understanding Bennu's chemistry helps scientists learn about how life emerged on Earth and how liquid water interacted with asteroids in the early Solar System. This knowledge can also help us better understand our own planet's history and the possibility of finding life elsewhere in the universe.