The moon’s shadow launched a ripple that was seen from Brazil an hour later
It was the eclipse felt ‘round the world. The August 21, 2017, total solar eclipse that crossed the United States launched a wave in the upper atmosphere that was detected nearly an hour later from Brazil (SN Online: 8/11/17).
“The eclipse itself is a local phenomenon, but our study shows that it had effects around the world,” says space scientist Brian Harding of the University of Illinois at Urbana-Champaign.
Harding watched the eclipse from St. Louis. But he and his colleagues activated a probe near São João do Cariri, Brazil, to observe uncharged particles 250 kilometers high in a part of the atmosphere called the thermosphere.
The probe recorded a fast-moving wave in the thermosphere go by half an hour after sunset in São João do Cariri and