This is more of a confirmation that I got the facts right: Reading around, I found out that the solar wind travels from the Sun to the Earth at a mean speed of 400km/s. Does this mean that it takes around 4 days for a burst of solar wind to cause disturbances in the Earth's magnetic field? What about x-ray flux? That would also cause disturbances in the Earth's magnetic field wouldn't it? Am I right in thinking that this could be detected after 8 minutes? Please can someone confirm that I got this right. If not let me know what I got wrong. Thanks a lot.