Meteoritic organic matter records primitive oxygen reservoirs of the solar system.

Primitive meteoritic organic matter from diverse carbonaceous chondrites retains oxygen isotope signatures near the CCAM line, indicating minimal alteration since formation.

• Why it matters: Understanding the formation and alteration of extraterrestrial organic matter is essential for revealing the chemical evolution of the solar system and the origins of life on Earth.
• What they did: High-precision triple oxygen isotope measurements were conducted on insoluble organic matter from various primitive carbonaceous chondrites, including CI, CM, CR, Bells, and Tarda types.
• The result: The findings show that meteoritic organic matter preserves primitive oxygen isotope signatures, providing insights into early solar system reservoirs and constraining models of organic matter synthesis and evolution.