A coronal hole, almost square in its shape, is one of the most noticeable features on the Sun of late (May 5-7, 2014). Credit: NASA
NASA has released amazing video footage showing what appears to be a hole on the surface of the sun. The astonishing clip, recorded in ultraviolet light last week by the space agency, shows a gigantic square-shaped black abyss manifesting itself on the solar surface. The so-called ‘coronal hole’ is itself a gap in the Sun’s magnetic field where solar wind streams out.
From the expert
“A coronal hole is an area where high-speed solar wind streams into space. It appears dark in extreme ultraviolet light as there is less material to emit in these wavelengths," says Dean Pesnell, official at NASA.
Hole's solar winds
If a coronal hole is facing us on Earth, the solar wind it emits buffets our own magnetic field, producing aurora lighting in the sky – even disrupting our communications systems. However, because this coronal hole is positioned so far south on the sun, “there is less chance that the solar wind stream will impact us here on Earth,” NASA officials said in a statement.
By the numbers
800 kilometers per second is how fast the winds blow inside the sun’s coronal hole – that’s 2.9 million kilometers per hour! This is approximately twice the speed of the normal solar wind, which is constantly streaming off the sun’s surface in every direction.