How magnetic waves interact with Earth’s bubble

Illustration of Earth's bow shock and magnetosphere - A new study involving UCL has uncovered how magnetic waves are transmitted past a standing shock wave, known as the bow shock, that forms ahead of Earth as a result of the solar wind hitting our magnetic bubble (magnetosphere). Shock waves occur in air when a plane travels faster than the speed of sound and also occur in plasma (a fourth state of matter that makes up 99% of the visible Universe) in space. Shock waves are believed to accelerate particles in supernovae (the explosions of stars) and in the jets released far into space by black holes. For the new study, published in Nature Physics , the international research team looked at magnetic waves that occur ahead of the Earth's shock (bow shock) known as foreshock waves. These are created by particles bouncing off the shock and travelling back towards the Sun. They used a computer model, Vlasiator, to simulate the physical processes at play in the transmission of these waves, finding waves on the other side of the shock with almost identical properties as in the foreshock. They then confirmed the presence of these waves using observational data from NASA's Magnetospheric Multiscale (MMS) mission.