The Sun formed approximately 4.6 billion years ago from a vast rotating cloud of gas and dust. The collapse of this cloud under its own gravity triggered nuclear fusion at its core, which is the source of the Sun’s power as we perceive it today.

Italian astronomer Galileo Galilei was the first to systematically observe the Sun using a telescope. He discovered huge black spots on the surface of the Sun, which we now refer to as “sunspots”. These findings shattered people’s illusion that the Sun was a perfect celestial body, and contributed to the advancement of the scientific revolution.

The sunspots discovered by Galileo are associated with intense magnetic activity on the Sun’s surface. This magnetic activity can cause explosive ejections of high-energy particles known as solar flares, which have the potential to damage power supply systems and electronic instruments in spacecraft and on Earth.

The high-energy particles ejected into space by the Sun can bring spectacular scenes to Earth. Earth’s magnetic field directs charged particles from the Sun towards the poles. When these charged particles interact with the atmosphere, beautiful auroras are produced.

In order to learn more about our Sun, scientists have constructed various telescopes for its observation. One such example is the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope located in Chile, which enables the study of the Sun’s atmosphere by observing lower-energy light waves.

The atmosphere that protects us absorbs X-rays, ultraviolet and other light waves in the Sun that are harmful to organisms. Therefore, in addition to telescopes on the ground, scientists have also sent some observatories into space to study the Sun from outside the atmosphere and across a wide range of wavelengths of light. These observatories allow us to observe and analyse different layers and features of the Sun in unprecedented detail, thereby providing scientists with a much more comprehensive understanding of our star.

Production & Copyright: ESO