Coronal holes on the sun can release jets of charged particles that may interfere with Earth’s atmosphere In a NASA photo that made the rounds on social media last week, the sun appeared to smile for the camera. The image, taken by the space agency’s Solar Dynamics Observatory satellite, was shared on one of NASA’s Twitter accounts. Social media users have compared the … [Read more...] about NASA’s ‘Smiling Sun’ Image Is a Reminder of the Threat of Solar Wind