Image of a large coronal mass ejection from the Sun in 2003. (Credit: NASA/ESA SOHO.)
Of all the issues facing the world right now that the US government is concerned about, the sun may seem to be an odd one. But the White House is taking the threat of a massive solar eruption seriously. Late last month, it released a new, largely overlookedreport outlining the risks of solar eruptions that strike the Earth — including the potential to cause massive, months-long power outages affecting upwards of 130 million people in the US alone, in one worst-case scenario. Still more troubling, the report — prepared by space weather experts from multiple government agencies — found that while the US is currently equipped with some of the best machinery for monitoring and forecasting such events, budget cuts over the next decade could put the country “at risk of losing critical capabilities that have significant economic and security impacts.”
“The potential for the Sun to unleash the big one is there,” said Michael Bonadonna, the report’s lead author and executive secretary for the National Space Weather Program, the agency in charge of coordinating these solar monitoring efforts. “It’s not a question of ‘if?’ but ‘when?’ and ‘are we ready?’”
“The big one,” that Bonadonna refers to is an extreme version of a regularly occurring type of solar event known as “coronal mass ejection,” or CME, for short. Starting in the Sun’s outer atmosphere (corona), a CME is a powerful blast of billions of tons of solar gas and parts of the Sun’s magnetic field, which fly toward Earth at around a million miles an hour. Such CMEs thin out as they travel through space over days, and by the time they arrive at our planet, most of them go unnoticed, causing only relatively minor disturbances to our planet’s own magnetic field.