Scientists Just Found Evidence That Asteroids May Have Helped Create Life on Earth

Scientists from the Korea Institute of Geoscience and Mineral Resources (KIGAM) have found evidence that asteroid impact craters may have played a key role in the emergence of oxygen-producing life on early Earth. Their study, published in *Communications Earth & Environment*, reports the discovery of stromatolites—layered rock formations created by ancient microbial communities—inside the Hapcheon impact crater, the only confirmed asteroid impact site on the Korean Peninsula. The stromatolites were identified in the crater’s northwestern section, measuring roughly 10 to 20 centimeters across. Researchers believe they formed in a hydrothermal lake created after a massive asteroid strike, where heat from molten rock kept the water warm and rich in minerals, fostering microbial growth. Stromatolites are typically linked to cyanobacteria, which produce oxygen through photosynthesis, and fossil records indicate they existed at least 3.5 billion years ago. The discovery suggests hydrothermal crater lakes may have acted as protected environments where oxygen-producing microbes thrived before the Great Oxidation Event (GOE), which occurred around 2.4 billion years ago. These isolated habitats could have served as localized ‘oxygen oases,’ allowing microbial ecosystems to develop before oxygen became widespread in Earth’s atmosphere. Chemical analysis of the stromatolites revealed traces of both extraterrestrial material and local bedrock, along with signs of high-temperature water activity. The innermost layers showed stronger hydrothermal signatures, indicating they formed during an early, hotter phase of the crater lake’s history. The evidence supports the idea that the stromatolites developed in a post-impact hydrothermal lake that gradually cooled over time. The findings also have implications for ancient Mars, where scientists believe similar impact craters may have once contained water. Researchers suggest such environments could be promising sites to search for evidence of ancient microbial life. The study builds on earlier work published in *Gondwana Research* in 2021, which first confirmed the Hapcheon crater’s impact origin. Lead author Dr. Jaesoo Lim stated this is the first comprehensive evidence that stromatolites could form in hydrothermal lakes created by asteroid impacts, potentially offering new insights into early microbial ecosystems on Earth.