You know where you’re not going to catch the coronavirus? Space, that’s where. But you will catch a glimpse of beautiful halos around the sun and other celestial bodies. The word “corona” has Latin roots, meaning essentially “crown.” The solar corona is the outermost region of the Sun’s atmosphere, a hazy aura made of colder plasma that is released from the surface of the star. It’s most visible during a total solar eclipse, one reason heliophysicists (sun scientists) get so excited about these rare events. This week we will zip around the solar system in search of coronas, no hand-washing required.

solar corona
The sun’s corona is made of solar plasma, but it’s not visible most of the time. When the sun is blocked by the moon, however, we get a full light show that reveals the ever-changing shape of the sun’s atmosphere.Photograph: Carla Thomas/NASA
solar coronal mass ejection
This handle-shaped prominence–the length of several Earths–is a burst of plasma shooting out through the sun’s corona, which appears here as a fine haze.Photograph: ESA/NASA/SOHO
large sunspot
This image taken in 2017 by the SOHO spacecraft essentially shows an artificial eclipse as a way to study the corona: The blue disk is blocking the sun, indicated by the white circle. That massive flare on the right is called a CME, or coronal mass ejection. These ejections are created when openings in the sun’s magnetic field spit out the highly charged particles that are responsible for the auroras here on Earth. At the upper left you can see Venus moving across the image; Mercury is at the lower left.Photograph: NASA Goddard
moon's corona refracted through high cloud
When a corona appears around the moon, it’s because of particular conditions in our own atmosphere that affect how we see the light reflected off it.Photograph: Jamie Cooper/SSPL/Getty Images
venus surface corona
Venus was once covered in active volcanoes and that fiery history has left its mark. This circular feature, also called a corona, was created by ancient lava flow. This whole region, called Artemis Chasma, spans just over 2,000 miles across.Photograph: NASA/JPL
Venus tracks and surface corona
In 1991 NASA’s Magellan spacecraft captured the cracks and corona on the surface of Venus. You can see some younger impact craters, as well as cracks from plate tectonics; that main circular feature is a corona created by past volcanic activity.Photograph: NASA/JPL

Once you’re done here, head overhere for more space photos.


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