In this image taken on 22 December 2017, an elongated coronal hole on the Sun (the darker area near the centre of the picture) takes the shape of a single, recognisable question mark.
Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of the streaming plasma we call solar wind.
Originally published by Cosmos as A solar question
Cosmos
Curated content from the editorial staff at Cosmos Magazine.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
