In 1859, a massive space storm hit Earth, frying telegraph communications in the United States and Europe. Bright aurorae shone worldwide, and astronomers concluded that the so-called Carrington event (named after the U.K. astronomer Richard Carrington, who discovered it) had affected the entire globe. But new findings suggest instead that relatively few spots on Earth were hit by the storm. To make the discovery, scientists analyzed the impact of two similar but less intense storms in 2003 and 2005. Like Carrington, both were caused when a ball of hot, electrically charged gas from the sun slammed into Earth’s magnetic field (artist’s impression above), temporarily weakening it, creating worldwide aurorae and taking out all the power in Sweden’s third-largest city in one case. Both recent storms weakened Earth’s magnetic field after just minutes, according to solar readings from satellites and magnetic strength readings from ground sensors. It would have taken more than an hour for a space storm to affect the field everywhere on Earth. The patterns of the changes in magnetic field strength over 48 hours seen in these two events were so similar to those recorded in a ground sensor during the Carrington event that the first event must not have been global in its reach either, the team reports in the Journal of Space Weather and Space Climate. That’s good news for our future, because if such events were indeed global, they would have catastrophic consequences such as wiping out telecommunications and power grids worldwide. Still, localized regions could still experience these effects, so we’re not out of the storm yet.