The line following the title of BBC's Elon Musk SpaceX rocket on collision course with moon reads:
A rocket launched by Elon Musk's space exploration company is on course to crash into the Moon and explode.
The collision is due to happen on 4 March when the rocket will explode as it makes contact.
In 2009 Prof (Jonathan) McDowell and other astronomers performed an experiment in which a similar-sized rocket was crashed into the Moon. Sensors gathered evidence of the collision so they could study the crater.
That means scientists are unlikely to learn anything new from this crash, Prof McDowell explains.
To me the article suggests that McDowell's view of the current crash is "been there, done that".
Question: In 2009 did Prof Jonathan McDowell and other astronomers perform an experiment in which a similar-sized rocket was crashed into the Moon? If so, which rocket? How did they crash it? What did they measure, and what (if anything) did they learn?