New study questions the age of Earth's oldest impact crater

In March 2025, researchers from the Curtins School of Earth and Planetary Sciences along with the Geological Survey of Western Australia made a significant announcement about Earth's oldest impact crater located in Western Australia. Initially, it was estimated to have formed about 3.5 billion years ago, potentially making it over a billion years older than the previously recognized record holder, the Vredefort structure in South Africa. However, the validity of this timeline has come under scrutiny due to a new study conducted by Aaron J. Cavosie from Curtin University and Alec R. Brenner, a Yale University postdoctoral researcher. The original discovery was based on geological investigations that included the examination of shatter cones, which are formations created under extreme pressure during an impact event. On one hand, the initial study reported finding these shatter cones in sediment layers dated at 3.47 billion years old, concluding that the impact must have occurred over 3 billion years ago. In contrast, the newer research presented evidence that varied the estimated age of the impact crater by examining the surrounding geological context more closely. A subsequent field survey identified additional shatter cones present in basaltic lava layers that overlay the sediment, indicating that the impact could have occurred later than previously determined, specifically after the formation of these younger basaltic rocks, which were dated to be around 2.77 billion years old. Using different methodologies, the new study recalculated the size of the crater based on the orientation of these shatter cones rather than their distribution, asserting that the actual diameter of the crater is approximately 16 kilometers. This represents a significant reduction from the original estimate of 100 kilometers, casting further doubt on the earlier findings. While this revised crater may not claim the title of the world’s oldest or largest, it retains a unique scientific value due to its formation within a large basalt plateau, a setting relatively rare for impact craters. Additionally, the proposed name for the crater, "Miralga impact structure," pays homage to the Aboriginal name of the region. This reinforces the idea that scientific research can intersect with cultural significance, preserving a connection to history and legacy. The new study titled, "Geology and Mars analog potential of the <2.7-billion-year-old Miralga impact structure, North Pole Dome, Pilbara Craton, Australia," was published in the journal Science Advances, signifying an important contribution to the understanding of Earth’s geological timeline and its implications for planetary science as well.