Luna 16 was the first Soviet spacecraft to return samples from the Moon to Earth without carrying astronauts.
The mission landed in the Mare Fecunditatis region on 20 September 1970. Its landing craft drilled into the lunar surface, collected soil, and transferred the material to a small return capsule. That capsule lifted off from the Moon and landed in the Soviet Union on 24 September.
Luna 16 returned about 101 grams of lunar material. The achievement was important because it demonstrated that robotic spacecraft could complete a sample-return mission without the cost and risk of a crewed landing.
Luna 15 had attempted a lunar sample-return mission in 1969 but failed before it could deliver material. Luna 20 and Luna 24 later expanded the Soviet robotic sample-return program. Luna 16 is therefore distinguished by being the first successful robotic lunar sample-return mission, not the first spacecraft to land softly on the Moon.