Solar storm of 1859 - Wikipedia, the free encyclopedia:
The solar storm of 1859, also known as the Solar Superstorm, or the Carrington Event, was the most powerful solar storm in recorded history.
From August 28 until September 2, numerous sunspots and solar flares were observed on the sun. Just before noon on September 1, the British astronomer Richard Carrington observed the largest flare, which caused a massive coronal mass ejection (CME), to travel directly toward Earth, taking 18 hours. This is remarkable because such a journey normally takes three to four days. It moved so quickly because an earlier CME had cleared its way.
From September 1–2, the largest recorded geomagnetic storm occurred, causing the failure of telegraph systems all over Europe and North America. Auroras were seen all over the world, most notably over the Caribbean; also noteworthy were those over the Rocky Mountains that were so bright, the glow awoke gold miners, who began preparing breakfast because they thought it was morning.