How many space rocks hit the moon every year?
One of the numerous risks that NASA had to foresee before sending humans to the moon in 1969 was space pebbles piercing astronauts' spacesuits or other equipment. The moon is susceptible to whatever rocks, or even particles, are flying around in space, unlike Earth, which has a protective atmosphere in which meteoroids often disintegrate. Thankfully, Bill Cooke, director of NASA's Meteoroid Environment Office at NASA's Marshall Space Flight Center in Alabama, said that the crew weren't in too much danger. According to Cooke, the likelihood of an astronaut being struck by a millimeter-sized item occurs around once in a million hours per person. The maximum size of a meteoroid that can enter a spacesuit for an astronaut is one millimeter. Understanding how often our natural satellite is struck by objects is crucial since NASA is gearing up to return people to the moon by 2025 and eventually build a base there or in orbit around it. How many things thus strike the moon dai...