Oldest crater on Earth formed due to comet impact

A comet may have been responsible for creating one of the largest and oldest known impact craters on Earth, a new study suggests.
The Sudbury Basin located in Ontario, Canada is one of the largest known impact craters on Earth, as well as one of the oldest due to its formation more than 1.8 billion years ago.
Researchers who took samples from the site and subjected them to a detailed geochemical analysis say that a comet may have hit the area to create the crater.
"Our analysis revealed a chondritic platinum group element signature within the crater's fallback deposits; however, the distribution of these elements within the impact structure and other constraints suggest that the impactor was a comet," said Joe Petrus, lead author of the research paper.

"Thus, it seems that a comet with a chondritic refractory component may have created the world-famous Sudbury basin," said Petrus.
The study was published in the journal Terra Nova.