Question: when did the rocket land on the moon

title: Moon landing
text: The GRAIL mission consisted of two small spacecraft : GRAIL A ( Ebb ) , and GRAIL B ( Flow ) . They were launched on 10 September 2011 on board a Delta II rocket . GRAIL A separated from the rocket about nine minutes after launch , and GRAIL B followed about eight minutes later . The first probe entered orbit on 31 December 2011 and the second followed on 1 January 2012 . The two spacecraft impacted the Lunar surface on 17 December 2012 .