The robotic rover Curiosity has instruments that detect radiation both inside the spacecraft and in the Mars environment. What is most likely the purpose of this radiation detection? to determine whether human exploration of Mars is possible to develop better X-ray technology to find evidence of once-living Martian microorganisms to investigate evidence of hydrogen and water

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

technology is the application of the knowledge gained by science.