Giant ‘hole’ spotted in Sun, spewing super-fast solar wind directly at us: What’s unusual about this?

December 6, 2023  12:12

Not far from the equator of the Sun, a huge dark spot recently appeared - these are called coronal holes. From it, powerful streams of unusually fast radiation, known as the solar wind, rush towards the Earth.

According to scientists, the size and location of the time hole are unprecedented at this stage of the solar cycle. The hole formed near the solar equator on December 2 and reached a maximum width of about 497,000 miles (800,000 kilometers—about the size of 60 Earths side by side) in 24 hours, reports. Since December 4, this hole has been pointed directly at Earth.

Experts initially predicted that this hole could cause a moderate (G2) geomagnetic storm that would lead to radio blackouts and strong auroras over the next few days. However, the solar wind turned out to be less intense than expected, so the resulting geomagnetic storm is still assessed as weak (G1). But it's worth noting that auroras are still possible at high latitudes.

According to the National Oceanic and Atmospheric Administration (NOAA), it is unknown how long the hole will remain on the Sun, but previous coronal holes have existed for more than one solar revolution (27 days). One way or another, soon the hole will turn away from the Earth.

Coronal holes occur when the magnetic fields holding the Sun in place suddenly open up, causing the contents of the Sun's upper surface to be blown away as the solar wind. Coronal holes appear as dark spots because they are cooler and less dense than the surrounding plasma. Sunspots appear black for much the same reason, but unlike sunspots, coronal holes can only be seen when viewed under ultraviolet light.

According to NOAA, radiation flows from coronal holes are much faster than the normal solar wind, and they often cause disturbances in the Earth's magnetic field, known as geomagnetic storms.

Solar activity has been increasing throughout the year as the Sun approaches the explosive peak of its roughly 11-year solar cycle known as solar maximum. Typically, new coronal holes do not appear during increasing solar activity. Of course, coronal holes can occur at any point in the solar cycle, but in fact they are more common during solar minimum. And when they appear during solar maximum, they are usually located near the sun's poles rather than near the equator. So it remains a mystery how such a massive hole opened near the equator when we are so close to solar maximum.

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