Solar storm of 1859 (Carrington Event)

Background. The geomagnetic storm of 1859 is often called the Carrington Event due to the observations of Richard Carrington. The storm was likely caused by a coronal mass ejection from the Sun colliding with Earth's magnetosphere. This event was associated with a very bright solar flare on 1 September 1859, which was independently observed and recorded by British astronomers Richard Carrington and Richard Hodgson.

Astronomical Observations. Just before noon on 1 September 1859, English astronomers Richard Carrington and Richard Hodgson independently recorded the earliest observations of a solar flare. Their independent reports were published side by side in the Monthly Notices of the Royal Astronomical Society. They exhibited their drawings of the event at the November 1859 meeting of the Royal Astronomical Society.

Global Effects. The storm created strong auroral displays reported globally and caused sparking and fires in telegraph stations. Worldwide reports of the effects were compiled and published by American mathematician Elias Loomis, supporting the observations of Carrington and Stewart. A conversation between telegraph operators between Boston and Portland occurred on the night of 2 September 1859.