Living with Space Weather (Baby, It’s Charged Outside)
A solar storm, aurora from space, and aurora on Earth. Image credit NASA.
Space weather? Is that a real thing? As someone recently asked me, isn’t it pretty much always cold up there?
In a sense that’s true: the temperature in near-Earth space is actually thousands of degrees, but in the shade you’d freeze pretty fast. However, weather in space is not so much about extremes of temperature. Think instead of storms of magnetized plasma (ultra-hot protons and electrons) erupting from the Sun on a daily or near daily basis.
Up until a century or so ago, these Coronal Mass Ejections (CMEs) only affected humans on Earth in the form of auroral light shows. Technology has made us vulnerable, so that now space weather is something to be reckoned with. The question of how to do so — planet-wide — is the topic of a recently published international report, “Understanding Space Weather to Shield Society”.
Just as a hurricane drives rain, wind, and floods, the space weather arising from a solar eruption can come in different forms. First comes the light from a solar flare, disrupting high-frequency radio communications at the Earth more or less immediately (eight minutes after leaving the Sun). Next comes particle radiation from the flare and CME-associated blast waves, creating hazards for astronaut health, satellite function, and aircraft electronic systems. Finally, the CME itself arrives — the magnetized plasma that blows out from the Sun and takes 1-3 days to travel to the Earth. Interactions of the CME with the Earth’s magnetic fields creates colorful aurorae at high latitudes. More ominously, it can drive disturbances in the Earth’s upper ionized atmosphere (the ionosphere) that interfere with global navigation and communication systems, and can endanger electrical power grids —> Read More