Understanding vast systems in space requires understanding what‘s happening on widely different scales. Giant events can turn out to have tiny drivers — take, for example, what rocked near-Earth space in October 2003. On Oct. 28, 2003, and again on Oct. 29, massive solar flares erupted on the sun, sending X-rays zooming through the solar system. Along with the flares, the sun expelled giant clouds of solar material, called coronal mass ejections, or CMEs. The CMEs slammed into Earth‘s magnetic field pushed material and energy in toward Earth. This created what‘s called a geomagnetic storm.