Sun corona solar flare

The solar corona is the Sun's outer atmosphere, reaching millions of degrees, and solar flares are radiation bursts that affect space weather.

About this subject

The solar corona is the outermost region of the Sun's atmosphere, extending millions of kilometers into space. Visible to the naked eye only during total solar eclipses, it exhibits structures such as plumes, magnetic loops, and streamers, revealing the Sun's intense magnetic activity. The corona's temperature is puzzling: while the Sun's surface (photosphere) is about 5,500 °C, the corona reaches millions of degrees Celsius. This paradox is one of solar physics' greatest mysteries, possibly explained by plasma waves or magnetic reconnection.

Solar flares are violent bursts of electromagnetic radiation that occur near sunspots, releasing energy equivalent to billions of atomic bombs. They are associated with regions of strong magnetic fields and can last from minutes to hours. During the peak of the 11-year solar cycle, their frequency increases dramatically, potentially causing geomagnetic storms on Earth.

Studying the corona and solar flares is essential for forecasting space weather. Particles and radiation from these events can damage satellites, disrupt radio communications, and even overload power grids. Additionally, the auroras borealis and australis result from the interaction of these particles with Earth's magnetic field. Understanding these processes helps protect technology and astronauts in space missions.

Frequently Asked Questions

What is the solar corona?

The solar corona is the outermost layer of the Sun's atmosphere, made of extremely hot plasma (millions of degrees Celsius) and visible during total solar eclipses.

How hot is the solar corona?

The corona reaches temperatures of 1 to 3 million degrees Celsius, much hotter than the Sun's surface (about 5,500 °C), a paradox still under investigation.

How do solar flares affect Earth?

Solar flares release radiation and particles that can cause geomagnetic storms, disrupting satellites, communications, and power grids, as well as enhancing auroras.