Listening to NPR can occasionally turn up some real gems: Bonnie Buratti, a planetary researcher at NASA, decided to investigate a 50 year old controversy. In November 1953, physician and amateur astronomer Leon Stuart photographed what appeared to be an asteroid striking the moon and producing a brilliant fireball. Astronomers dismissed his claims and said the image was actually a burning meteor superimposed on the background of the moon. Buratti decided to investigate Stuart’s claim by poring over detailed photographs of the moon’s surface taken by the Clementine lunar probe. Clementine took over 2 million high resolution photos of the moon during the mid-1990’s, and Buratti looked for telltale signs of recent impacts on the lunar surface.
Buratti and Dr. Lane Johnson located a small, 2 kilometer wide crater, with a bright splash of lunar subsurface soil scattered around the impact site – a sure sign of its young age. The location of the crater matches the general location from Stuart’s 1953 photo, and the size of the crater is within the parameters extrapolated from the image of the impact. Buratti says the asteroid was roughly the size of a semi-truck and the energy of the impact was 35 times the strength of the atomic bomb detonated over Hiroshima. If this rock had struck the earth instead, it would have incinerated a small city.