Landsat 8 satellite has photographed an unusual geological structure in Australia. According to scientists, it represents the remains of an ancient impact crater.
About 600 million years ago, during the Ediacaran period, the Earth was very different. The landmass of our planet, which had only recently gone through a phase of global glaciation (the so-called Snowball Earth), was mostly barren and lifeless. However, there were many bizarre soft-bodied creatures that thrived in the shallow seas.
They may have been destroyed when the asteroid, which was about 200 to 400 meters in size, streaked across the sky and crashed into land or shallow water near present-day Davenport Ranges in northern Australia. Although much of the original impact crater has been eroded away, traces of the impact remain in the sedimentary and volcanic rock layers.
On February 3, 2025, the Landsat 8 satellite captured the site of an ancient impact, also known as the Amelia Creek impact structure. It created a canoe-shaped depression about 1 km wide and 5 km long. Analysis of satellite imagery shows that regional rock deformation extends approximately 10 km north and south of the impact crater, with minimal deformation to the east and west.
The long, narrow crater shape and regional deformation pattern are indications that the asteroid struck at an extremely oblique (small) angle. An asteroid impact at a steeper angle, like the one that killed the dinosaurs, would have left a deeper, more symmetrical crater and created an elevation at its center.
Other indications of collision at Amelia Creek are embedded in nearby quartzite rocks. Beginning in the 1980s, geologists discovered fan-shaped faults that were later identified as fracture cones. Such structures are only formed in collisions when shock waves pierce the rock. The fracture cones are all arranged in a crescent-shaped pattern mostly south of the crater, another indication that the asteroid struck at a low angle.
The amount of damage caused by the impact is unclear, but it is believed that asteroids falling to Earth at a low angle cause less damage than those falling at a steep angle. The small angle means that the object travels a greater distance through the Earth’s atmosphere, burns more of its mass, and often breaks into smaller pieces before impact.
Although from a planetary perspective the impact was probably localized, geologists collected evidence that two other larger impacts during the Ediacaran period may have had much more severe and even global consequences. They may have contributed to the extinction of a mysterious class of creatures called acritarchs and caused global changes in ocean chemistry and climate.
According to Earthobservatory
