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Japan’s Hinode spacecraft, which documents turbulent activity on the sun, is beaming back some intriguing video. A newly released movie shows the evolution of a polar crown prominence, a giant glowing loop of relatively cool gas hovering above the solar surface.

Prominences occupy rings, or crowns, at the sun’s poles that resemble Earth’s northern lights but are instead filled with sheets of highly ionized gas, or plasma. The solar prominence in the video is about 90,000 kilometers across and 30,000 km high. It could contain three Earths stacked one on top of the other. Researchers used to think that prominences were mostly stationary, anchored to the solar surface — at least temporarily — by the sun’s magnetic fields. But the video reveals several surprises, including narrow streams of plasma at the top of the prominence falling back to the bottom faster than magnetic fields would seem to allow. The recording also shows never-before-seen dark, tadpole-shaped plumes rising from the base of the prominence and swirls and vortices within the prominence.

Solar prominences form between oppositely directed magnetic fields, which, when they meet, unleash enormous amounts of energy and hurl billion-ton clouds of charged particles, known as coronal mass ejections. Prominences often lie at the core of coronal mass ejections, which, when headed toward Earth, can damage spacecraft and power grids. — Ron Cowen

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