1921 Geomagnetic Storm

14 May 2020

At https://spaceweather.com (3th May 2020) we learn that Comet Swan has cross the celestial equator and is now visible to observers in the northern hemisphere. Look east just before dawn - if you can drag yourself out of bed.

Back in May of 1921 there was a large geomagnetic storm reported across the US. It put out the signal system of the New York railway and it was blamed on the northern lights (or rather, a sunspot eruption). This was the biggest solar storm of the 20th century and even a hundred years ago people were aware of a connection between aurora, sun spots, and electrical systems on earth. It was front page news.

On May 12th a giant sunspot broke out as solar cycle 15 was coming to an end. Explosion after explosion hurled coronal mass ejections directly towards the earth's magnetic field. Magnetometers suddenly went off the scale, fires broke out at telegraph exchanges in Sweden and New York State. It seems that electrical currents induced by geomagnetic activity surged through telephone and telegraph lines, heating them to the point of combustion. Strong currents disrupted telegraph systems in Australia, Brazil, Denmark, Scandinavia, France, Japan, New Zealand, the UK and USA. During the storm's peak on May 15th temperatures in Los Angeles and Atlanta were similar to those of Fairbanks in Alaska on a normal day. Auroral lights danced overhead and telegraph lines crackled with current. Auroras were seen in Texas, Samoa, and Tonga, and ships in the Pacific near the equator (with a very broad view of the sky). A new study claims it was as powerful as the Carrington Event during the 19th century.

At the  same link but on 4th May we had the headline -the comet that refuses to die. It seems Comet Atlas has sparked back into life even though it split into 4 pieces.