The recently reported impact of a larger than expected micrometeorite on one of the mirror segments of the JWST (fortunately not serious) set me to thinking about the potential hazards from such impacts on interstellar travel.
Imagine the kinetic energy involved by being hit by something the size of a grain of sand (typical mass 0.004g) if the spaceship is travelling at say 10% of the speed of light (a minimum speed really for any realistic interstellar travel). Doing the ½mv^2 calculation gives a result of 1800MegaJoules (MJ). For comparison let's consider the kinetic energy of the shells fired from the largest ever gun fitted to a warship, the massive 18" guns of the Japanese battleship Yamato, which fired a 1460kg shell at a muzzle velocity of 780m/s. That works out at 444MJ, so our grain of sand hitting our hypothetical interstellar spaceship would have 4 times that energy, that's going to cause some serious damage! https://www.themeasureofthings.com/results.php... https://en.wikipedia.org/wiki/46_cm/45_Type_94_naval_gun
Imagine the kinetic energy involved by being hit by something the size of a grain of sand (typical mass 0.004g) if the spaceship is travelling at say 10% of the speed of light (a minimum speed really for any realistic interstellar travel). Doing the ½mv^2 calculation gives a result of 1800MegaJoules (MJ). For comparison let's consider the kinetic energy of the shells fired from the largest ever gun fitted to a warship, the massive 18" guns of the Japanese battleship Yamato, which fired a 1460kg shell at a muzzle velocity of 780m/s. That works out at 444MJ, so our grain of sand hitting our hypothetical interstellar spaceship would have 4 times that energy, that's going to cause some serious damage! https://www.themeasureofthings.com/results.php... https://en.wikipedia.org/wiki/46_cm/45_Type_94_naval_gun