A CRACK IN EARTH’S MAGNETIC FIELD: This morning, during the early hours of March 10th, a crack opened in Earth’s magnetic field. Solar wind poured in and “the sky exploded with auroras,” reports Kristin Berg who sends this picture from Tromsø, Norway:
“The air temperature was 10 degrees F below zero,” she says, “but the cold was a small price to pay to see a magnificent display like this.”
The “crack” was pried opened by the solar wind itself. Magnetic fields in the solar wind interacted with Earth’s magnetic field, partially cancelling our planet’s defenses against the oncoming gas. In the jargon of space weather forecasters, “B sub z tipped south.”
NASA and European spacecraft have been detecting these cracks for years. Some are as large as California, and sometimes they grow wider than the whole planet. They tend to form most often during weeks around equinoxes–a seasonal phenomenon known as the “Russell-McPherron effect,” named after the researchers who first studied and explained it.