Nasa's latest Mars rover, Perseverance, has sent back the sounds of its six metal wheels driving across the planet's surface. The recording was captured by one of its two onboard microphones, with Nasa releasing 16 minutes' worth. Engineers are investigating whether a high-pitched scratching noise is caused by electromagnetic interference or the rover's movement. Perseverance will continue to look for somewhere to launch the Ingenuity Mars Helicopter, a drone that it is carrying