A 2.2-billion-year-old crater is Earth’s oldest recorded meteorite impact
A 70-kilometer-wide crater in Western Australia has officially earned the title of Earth’s oldest recorded impact. Yarrabubba crater is a spry 2.2 billion years old, plus or minus 5 million years, researchers report January 21 in Nature Communications. Moving tectonic plates along with erosion have wiped away much of the evidence for many craters older than 2 billion years, leaving a gap in our understanding of how long-ago meteorite impacts may have affected the planet’s life and atmosphere (SN: 12/18/18). Scientists have uncovered ancient impact material older than 2.4 billion years from sites elsewhere in Western Australia and South Africa, but no corresponding craters. Yarrabubba, located on one of Earth’s oldest patches of crust called Yilgarn craton, adds more than 200 million years to the impact record. The previous record-holder was Vredefort crater in South Africa. Scientists had estimated Yarrabubba to be between 2.6 billion and 1.2 billion years old, based on previous research dating rocks around the impact site. In the new...