A discarded SpaceX Falcon 9 upper stage has crashed into the Moon after drifting through space for more than 18 months, ending an unusual journey that scientists say offers a rare opportunity to study lunar impacts and the risks posed by abandoned spacecraft. The 4,000-kg rocket slammed into the lunar surface at an estimated speed of 5,400 mph (8,690 kmph), with an impact equivalent to an explosion of three tonnes of Trinitrotoluene (TNT). Researchers expected the collision to create a crater measuring 20 to 30 metres wide, ejecting a plume of lunar dust high above the surface. The impact was predicted to occur at around 7.35 am UK time (12.05 pm IST). However, astronomers noted that the stream of ejected material could remain visible to telescopes for a short period.