In this TED-Ed lesson we discovered that careful observations of the Sun can help us predict when future solar storms will occur. The field of space weather, which deals with monitoring and predicting phenomena occurring between the Sun and our planet, is developing at a fast pace with new instrumentation and analysis techniques. The observation of the photosphere and the corona, the “surface” and the “atmosphere” of the Sun, as well as complex measurements of its ever-evolving magnetic field, can help us predict when the next solar storm will occur and its intensity.

Observations of the Sun pre-date the invention of the telescope by millennia. While current studies point to the Babylonians of the 8th century BCE as the first to produce systematic records of solar eclipses, only with the advent of the telescope in the 17th century CE did it become possible to pursue an accurate investigation of our star. For example, the renowned Italian scientist Galileo Galilei, who was the first to use the telescope for astronomical purposes, published a pamphlet in 1613 entitled “Istoria e Dimostrazioni intorno alle Macchie Solari” (History and demonstrations about sunspots, or “Letters on Sunspots” in brief), where he pointed out that the surface of the sun is “stained” by darker spots, which appear periodically. Note that this was a substantial blow to the Aristotelian model of the cosmos, which assumed that the sky was immutable.

Of course, observations of the Sun have improved significantly over the centuries, with the creation of solar towers, better solar filters (never observe the Sun with naked eyes!), and eventually, with the development and launch of solar observatories in space. The first space-based solar observatory was launched in 1962 by NASA and was called Orbiting Solar Observatory, or OSO. Among the most successful space-based solar observatories is the Solar and Heliospheric Observatory (SOHO) launched in 1995 and the recent Solar Dynamics Observatory (SDO) launched in 2010.

However, the real protagonist of this dig deeper section is a ground-based solar observatory. The Daniel K. Inouye solar observatory, with its 4-meter telescope in Hawaii, is currently the most powerful observatory of this kind in the world. Its cutting-edge technology in terms of adaptive optics allowed this facility to reach unprecedented angular resolution images of the surface of the Sun.

At the beginning of 2020, the Inouye telescope released this image, which is currently the highest-resolution photo of the photosphere ever made. The golden granularities that you can observe are in fact immense bubbles of incandescent plasma, each one the size of Texas! The smallest features seen in the image are about 18 miles, or 30 km in size.

With the help of these images and with all the data collected by this and other telescopes around (and above!) the world, scientists are acquiring a better understanding of the structure and evolution of our Sun. This will improve space weather forecasts and help us prepare for the next solar storm. Solar scientists, with the help of their ever-advancing instruments, will do whatever it takes to keep our lights on.

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