These are the most-read Science News stories of 2021

Blue jet lightning

The International Space Station spotted the origins of a bizarre type of upside-down lightning called a blue jet (illustrated) zipping up from a thundercloud into the stratosphere in 2019. The discovery ranked among Science News' most-read stories of 2021.

DTU SPACE, DANIEL SCHMELLING/MOUNT VISUAL

Science News drew over 21 million visitors to our website this year.