Astrophotographer captures 100,000 km high 'plasma waterfall' on Sun

An astrophotographer from Argentina, Eduardo Schaberger Poupeau, captured a spectacular image of a polar crown prominence (PCP), a large wall of plasma that collapsed toward the solar surface at incredible speeds after being ejected near the sun's south pole, Space.com reports.

Poupeau used specialized camera equipment to take the picture on March 9, which shows the plasma wall rising 100,000 kilometers (62,000 miles) above the solar surface, equivalent to eight stacked Earths. The plasma appeared like multiple threads dripping down a wall, Poupeau said.

PCPs are similar to solar prominences, which are plasma loops ejected from the sun's surface by magnetic fields. However, PCPs occur at latitudes between 60 and 70 degrees North and South, near the sun's magnetic poles, where the magnetic fields are stronger, causing the plasma to collapse back towards the sun, earning them the nickname "plasma waterfalls."

The plasma within PCPs is not in freefall as it remains contained within the magnetic field that ejected it, but it travels downward at speeds of up to 22,370 mph (36,000 km/h), much faster than the magnetic fields should allow based on experts' calculations. Researchers are still trying to understand how this is possible.

A study published in 2021 revealed that PCPs have two phases during their eruptions: a slow phase, where plasma shoots upward, and a fast phase, where plasma accelerates towards its altitude peak. Further research is needed to determine if this affects how the plasma falls back to the surface.

Solar physicists study solar prominences due to their association with coronal mass ejections (CMEs), magnetized plasma plumes that can break away from the sun and impact Earth. PCPs are also of interest to nuclear physicists since the sun's magnetic field appears to contain the plasma loops in the polar regions, which may provide insights that help improve experimental nuclear fusion reactors. PCPs are relatively common and could happen almost every day, though images like the one captured by Poupeau are rare. However, they could become more frequent and intense as the sun ramps up to its 11-year solar cycle peak, known as the solar maximum.

In February 2022, a massive solar prominence broke off from the sun and became trapped in an enormous, fast-moving polar vortex around the sun's north pole for around eight hours. On September 5 and September 24, 2022, respectively, an enormous, undulating stream of plasma shot across the solar surface like a snake, and a colossal 1-million-mile long plume of plasma erupted from the sun's surface after another prominence snapped in half.