The sun’s surface has been a hot topic amongst scientists for generations, with the first image of the sun being taken way back in 1845 by French Physicist Louis Fizeau. The photograph only captured the star as a black and white image. This starkly contrasts the newest image of the sun, which shows a bright, complex honeycomb looking surface.
The sun, which is 149.6 million kilometers away, has a surface area of 11, 990 times that of the Earth meaning that theoretically one million Earths could fit inside the sun. This value will only ever increase; as the sun ages, not only is it getting brighter, but its outer envelope is slowly expanding, and it will eventually engulf the Earth. This is due to the nuclear fusion of two hydrogen nuclei into one helium atom. However, this isn’t meant to happen for roughly eight billion years (when it reaches twelve billion years of age). The Sun’s surface has never been captured with this level of clarity until now, thanks to the development of the Inouye solar telescope.
Based on the summit of Haleakala volcano in Hawaii, the National Science Foundation’s Daniel K. Inouye Solar Telescope began construction in 2010. This is the world’s largest solar telescope; its construction cost £265 million to build. Sitting at 3,000m and displaying a four-metre wide mirror, the structure of the telescope allows near-infrared wavelengths to be observed. Solar telescopes, however, suffer from one huge problem: heat is generated by tightly focused sunlight. The Inouye telescope has built in ways to combat this issue: a large dome which encloses the telescope and is covered by thin cooling plates that stabilize the temperature both inside and outside of the dome, shutters that provide shade and air circulation, and most importantly, a feature called ‘heat stop’ which blocks the sunlight’s energy from the main mirror. Thanks to its unique sensitivity and high resolution, it was able to give the most intricate image of the sun’s surface to date. The image shows larger cell-like structures, which look deceivingly small considering each cell is around the size of Texas.
The new telescope hopes to uncover the mysteries of the sun. It aims over the next 44 years to map the magnetic fields within the Sun’s corona, and better our knowledge of the dynamic behaviour of the sun’s solar flares and intense heat. Mapping the magnetic field will also better our understanding of what drives solar storms, therefore making us better equipped to be able to predict them. Inouye has made it possible to get a closer look at the Sun’s plasma, which affects the magnetic fields around the sun. As the magnetic fields twist, this leads to solar storms. Inouye is able to measure and characterise the Sun’s magnetic field to look for this solar activity. This ‘space weather’ / solar activity on the Sun can affect many systems on the Earth. The magnetic eruptions can disrupt satellite communications, bring down power grids and impact air travel.