Science blog

13 September 2019

The sixtieth anniversary of the first human created object to land on the Moon, Luna 2

Earlier this year, there was much commemoration of the fiftieth anniversary of the first landing by humans on the Moon, by Neil Armstrong and Buzz Aldrin of Apollo 11. Today is the sixtieth anniversary of an earlier achievement, the first human-created object to land on the Moon (or any celestial object other than Earth). This was the Soviet probe Luna 2, which landed on the Moon on the 13th Sep 1959 (the 14th by USSR time), after being launched around one and a half days before. The third and final stage of the probe's launch rocket also hit the lunar surface, in an uncertain location.

A policed metal globe of tesellating pentagons, each marked CCCP 1959
Copy of the ball of plaques carried on Luna 2, now displayed at the Kansas Cosmosphere. Photograph by Patrick Pelletier, used under a CC BY-SA 3.0 licence.

There is also a British element to this event. Some people in the USA and other western countries had suspected that previous spaceflight achievements by the Soviet Union had been exaggerated or entirely faked for propaganda purposes. Due to this, the astronomer Bernard Lovell, the founder of the Jodrell Bank radioobservatory, acted as an independent witness to prove that Luna 2 actually had been launched and had reached the Moon.

Luna 2 was designed by the leading USSR space systems designer Sergei Korolev. The probe carried equipment to investigate the Earth's magnetic field, radiation, cosmic particles, and micrometeor impacts. A previous, similar probe, Luna 1, had been launched in January, but missed the Moon due to a failure of control of the rocket. Luna 2 successfully landed in the Palus Putredinus region. Luna 1 and Luna 2 confirmed that there was no measurable magnetic field or radiation belt around the moon. The next successful Soviet Moon probe, Luna 3, successfully orbited the moon and took the first photographs of its dark side. Later, in 1966, Luna 9 became the first human-made object to make a controlled soft landing on the moon.

Moscow Cosmos sent Lovell tracking data for Luna 2 and radio frequencies provided by USSR news reports. Jodrell Bank telescope picked up signals from satellite from claimed position exactly as required on two separate occasions. US astronomers were sceptical until Lovell held the telephone handset to the loudspeaker so that they could hear the bleeps. The apparent signal frequency of the transmissions changed due to Doppler shift exactly as predicted from acceleration of the probe under lunar gravity. The last signal was detected from 50 miles above the Moon's surface and the end of the transmission was too abrupt for the satellite to have passed behind the moon. Luna 2 hit the Moon's surface at 22:02:23 BST on 13th Sep 1959 at 7500 mph. The launching rocket also emitted a cloud of glowing vapourised sodium once it had reached 97000 miles from Earth, so that it could be more easily tracked. The probe incorporated a hollow titanium ball covered with Soviet symbols, which was intended to break up on impact and scatter them over the landing site.

An image of craters on the Moon with a close up of a probe.
The later USSR Luna 16 mission landed on the Moon, photographed by the US Lunar Reconnaissance Orbiter. Photograph used by permission from NASA for informational purposes.

Lovell, B, Here is the evidence that the Moon was hit, LIFE 47(13), 28 Sept. 1959, p. 53
Lund, T, Early exploration of the Moon: Ranger to Apollo, Luna to Lunniy, Cham: Springer, 2018. Available as an ebook in British Library Reading Rooms.