INTERPLANETARY SHOCK WAVE: Surprising forecasters, a shock wave buried in the solar wind hit Earth's magnetic field today, sparking rare blue auroras around the Arctic Circle. The source of the shock *might* have been a magnificent eruption on the sun, previously expected to miss our planet. Get the full story from Spaceweather.com.
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Above: Auroras over Abisko, Sweden, sparked by the interplanetary shock wave on Jan. 11, 2021. More:aurora webcam.
