The sun seems very ‘completely happy’ as we speak in NASA’s newest Photo voltaic Dynamic Observatory (SDO) photos. However do not be fooled by its cheery look — that ‘face’ is spewing huge streams of solar wind that might set off a solar storm on Earth, albeit a quite delicate one.
The three darkish patches that make the sun‘s ‘ face’ are coronal holes — areas of open magnetic area line constructions that permit solar wind to readily escape (opens in new tab) as a substitute of looping again on themselves. Torrents of solar materials can surge out of coronal holes at speeds of as much as 1.8 million mph (2.9 million kph), in keeping with the Exploratorium, (opens in new tab) a science museum in San Francisco. The areas seem darkish as a result of they’re cooler and fewer dense than the encircling plasma areas.
