Another theory on the formation of the Moon

At www.bbc.co.uk/news/science-environment-19011013 details of another theory on the formation of the Moon begins by saying it 'is certain that some sort of impact from another body freed material from the young Earth' and the debris coalesced into our Moon. Still, journalists are allowed some rope  and Auntie does like to play along with consensus ideas of various persuasions. Too bothersome to look into anything any rigour. What is open to debate, we are assured, is not the impactor – that is a given. It is the size and speed of the impactor. However, as you'll be pleased to know, computer simulation has come to the rescue. The impactor was apparently faster and bigger than expected and struck a glancing blow.