NASA’s Solar Dynamics Observatory (SDO) space probe has discovered a square-shaped coronal hole in the Sun’s corona, the outer part of the atmosphere of our star. It’s far south on the Sun so it’s unlikely that the solar wind originated in that area reaches Earth.

Coronal holes were discovered thanks to the X-ray telescopes in the Skylab space laboratory, which have been able to study the solar corona beyond the Earth’s atmosphere. Despite the name, they’re not holes but areas in which the Sun’s corona is darker and colder than the surrounding areas and where plasma has a lower density. During the solar minimum, coronal holes can be found especially in the polar regions of the Sun, instead during the solar maximum they can be found on its entire surface.

The peak of the solar cycle, which lasts 11 years, was reached last year. At that time, the Sun produced more sunspots and solar flares than normal. For this reason, there were concerns because solar flares can have effects on Earth. Despite the presence of the Earth’s magnetic field that acts as a shield, a particularly violent solar flare can disturb radio broadcasts and, in severe cases, even damage the electricity grid.

[ad name=”AmazonScience”]

The SDO spacecraft was launched on February 11, 2010, with the goal of studying the Sun and its influence on the Earth and on the surrounding space. During these four years, among its many observations there are also those of coronal holes. These phenomena can have any shape and size so the fact that the one observed in recent days has an almost exactly square shape is just a coincidence.

To be precise, the images included in the short video published by the team that runs the SDO mission at NASA  were taken between May 5 and 7. The SDO mission is one of the few currently focused on the study of the Sun and is important because solar activity has a strong influence on Earth. In this case, it discovered a phenomenon that actually isn’t exceptional from the scientific point of view but is certainly curious.