Fixing a Hole

'Fixing a hole where the rain gets in' was a reflection on the difficulties presented by persistent fans for the Beatles. But the hole that appears in the sun right now may present a different set of difficulties for us earthlings.

The hole in the sun is a gap in the sun’s magnetic field where charged particles are being expelled at speeds up to 500 miles per second (1.8 million miles per hour!). It’s not small like a sunspot, it’s something like 50 earths wide. The strong solar wind being ejected is producing fantastic auroras as it hits the earth’s atmosphere. These ionized particles can also influence radio transmissions, which could impact all types of communications on earth. And the solar wind has been implicated in the production of clouds, clouds that have a direct influence on earth’s weather.

The hole has been followed by a ‘prominence eruption’ in which a gas cloud loosely held by the sun’s magnetic field suddenly falls apart with much of the mass being shot out into space. If these eruptions are directed our way they can cause magnetic storms here on earth.

One such solar storm, known as the Carrington event, hit earth in 1859. In that storm a solar prominence eruption hit Earth's magnetosphere and induced perhaps the largest geomagnetic storm on record. English astronomer Richard C. Carrington observed a so-called ‘white light flare’ on the sun at the time. A similar sized solar storm occurring today would likely disrupt all sorts of electrical systems that are critical to modern civilization. In 2012 a huge solar storm occurred, but it was directed away from earth, saving us from any problems.

Last month our neighborhood star featured a rather unusual collection of three coronal holes appearing together. The coronal holes are the dark areas in the photographs – these are false color images taken in ultraviolet wavelengths that are invisible to the human eye.

There is a great deal that we do not understand about the sun, including how features like coronal holes and prominence eruptions form. What we do know is that the sun supplies the energy for life on earth, so we continue to study it.