The Sun is our closest star, and without it life on our world could not survive. So it is essential to understand its nature. And yet, even though the Sun shines brightly on every clear day on Earth, it is difficult for astronomers to observe the star closely for a number of reasons.
Most obviously, it is hot—so hot, it is difficult to get too close without getting burnt to a crisp. Additionally, due to high solar gravity, it requires a lot of energy to insert a spacecraft into an orbit near the Sun. The harsh radiation near the Sun also plays havoc with the scientific instruments on spacecraft.
For all of these reasons, while astronomers have made steady progress in understanding the Sun and its effects on Earth, our atmosphere, and other bodies in the Solar System, we still have big questions. The good news is that we are now entering the golden age of Solar research with a major new ground-based telescope and two space-based observatories that will come close to the Sun.
"There is no doubt that the observations and insight will be unprecedented—exploring new regions with new instruments in incredible detail," David Alexander, a solar physicist at Rice University and director of its space institute, told Ars.
First light in Hawaii
You may have seen the amazing images recently released by the Daniel K. Inouye Solar Telescope, which is located on a mountaintop at 3,084 meters in Maui, Hawaii. With a 4-meter aperture, it is the world's largest solar telescope. The new images were part of the first test observations, with routine science observations set to begin this summer.
Images and video of the Sun from the telescope showcase features as small as 30km, the best resolution ever observed. Cell-like structures about the size of Texas—they also look like popcorn, or small nuggets of gold—boil across the Sun's surface, bringing heat from the interior of the star to the surface. This hot plasma then cools slightly and sinks back below the surface of the Sun. It is all rather mesmerizing.