When did a spacecraft first land softly on the Moon?

Before Luna 9, spacecraft had only crashed into the Moon or photographed it from orbit or flybys. Luna 9 used retro-rockets to slow its descent, and its landing capsule was ejected and bounced to a stop on the Ocean of Storms. It then unfolded petal-like covers and transmitted panoramic images. Its success proved the lunar surface was firm enough to support a landing craft, easing fears that a spacecraft might sink into deep dust. The US Surveyor 1 made America's first soft landing four months later, in June 1966.