Luna 2 (E-1A series) was the second of the Soviet Union's Luna program spacecraft launched in the direction of the Moon. It was the first spacecraft to reach the surface of the Moon, and it impacted the lunar surface west of Mare Serenitatis near the craters Aristides, Archimedes, and Autolycus.[1] Luna 2 was similar in design to Luna 1, a spherical spacecraft with protruding antennae and instrument parts. The instrumentation was also similar, including scintillation counters, geiger counters, a magnetometer, Cherenkov detectors, and micrometeorite detectors. There were no propulsion systems on Luna 2 itself.

Scientifically, Luna 2 is most famous for confirming the earlier detection of the solar wind by Luna 1, via its hemispherical ion traps designed by Konstantin Gringauz. Luna 1 had provided the first evidence of this phenomenon; on Luna 2, Gringauz changed the four sensors to a tetrahedral arrangement, instead of planar, to get better measurements of the plasma flux.
After launching on September 12, 1959, Luna 2 separated from its third stage, which travelled along with it towards the Moon. On September 13 the spacecraft released a bright orange cloud of sodium gas, which aided in spacecraft tracking and acted as an experiment on the behavior of gas in space. On September 14, after 33.5 hours of flight, radio signals from Luna 2 abruptly ceased, indicating it had impacted on the Moon. The impact point, in the Palus Putredinis region, is roughly estimated to have occurred at 0 degrees longitude, 29.1 degrees N latitude. Some 30 minutes after Luna 2, the third stage of its rocket also impacted the Moon. The mission confirmed that the Moon had no appreciable magnetic field, and found no evidence of the Moon having radiation belts.

Wikipedia: http://en.wikipedia.org/wiki/Luna_2