The camera system aboard NASA’s Moon orbiting spacecraft survived a hit by a tiny meteoroid in 2014 which was travelling much faster than a speeding bullet, the U.S. space agency has said.
On October 13, 2014, the Lunar Reconnaissance Orbiter Camera (LROC), which normally produces beautifully clear images of the lunar surface, captured an image that was wild and jittery.
From the sudden and jagged pattern of the image, the LROC team determined that the camera must have been hit by a tiny meteoroid, a small natural object in space.
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LROC is a system of three cameras mounted on the LRO spacecraft. Two Narrow Angle Cameras capture high resolution black and white images. The third Wide Angle Camera captures moderate resolution images using filters to provide information about the properties and colour of the lunar surface.
According to Mark Robinson, principal investigator of LROC at Arizona State University in the U.S., the jittery appearance of the image captured is the result of a sudden and extreme cross-track oscillation of the camera.
The LROC team ran simulations to see if they could reproduce the distortions and determine the size of the meteoroid that hit the camera.
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They estimate the meteoroid would have been about half the size of a pinhead (0.8 millimetre), assuming a velocity of about seven kilometres per second and a density of an ordinary chondrite meteorite (2.7 grams per cubic centimetre).
“The meteoroid was travelling much faster than a speeding bullet. In this case, LROC did not dodge a speeding bullet, but rather survived a speeding bullet!” said Mr. Robinson.