(1) If a micrometeoroid or piece of space debris penetrates the tank, the dregs can ignite, causing an explosion that shatters the rocket body and creates a cloud of debris.(2) Other factors include charged particle radiation, neutral atomic particles, magnetic fields, micrometeoroids , and changes in gravity, not to mention environmental factors imposed by the spacecraft itself and the launch vehicle.(3) Hazardous micrometeoroids and radiation also threaten spacewalkers, and with no atmosphere and therefore no atmospheric pressure, fluids in the human body would boil.(4) He or she points out that the shuttle would be less exposed to micrometeoroids and orbital debris at the altitude of Hubble than at the lower altitude of the space station.(5) The moon lacks the shield provided by even a thin planetary atmosphere, such as Mars, so lunar explorers will have to withstand the relentless bombardment of harmful solar radiation and pelting rain of micrometeoroids .(6) A chemical analysis of impact crater residue allowed him to distinguish between impacts due to naturally occurring micrometeoroids and those due to artificial space debris.