The image above shows an oddity that NASA’s Solar Dynamics Observatory has rarely observed before: a dark filament encircling an active region, spotted in late October this year.
Solar filaments are clouds of charged particles that float above the sun, tethered to it by magnetic forces. They are usually elongated and uneven strands. Only a handful of times before have scientists seen one shaped like a circle.
The black area to the left of the brighter active region is a coronal hole, a magnetically open region of the sun. While it may have no major scientific value, it is noteworthy because of its rarity. The still was taken in a wavelength of extreme ultraviolet light.
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.