Astronomy, a science born of darkness, owes an awful lot to our nearest source of light. After all, so much of what we know about other stars—their makeup, the way they form larger systems—is extrapolated from our study of the sun.
Yet it is all but impossible to sidle up to the sun and ask what makes it tick. Computer simulations can help, but they still can’t accurately predict things like solar flares, which can wreak havoc on Earth. To construct new views of the sun, scientists are using the most powerful computers ever built, combined with some of the oldest instruments in the history of astronomy.
“The sun is the most important astronomical object for humanity,” says Joe McMullin, project manager for the Daniel K. Inouye Solar Telescope (DKIST), a massive observatory being built on Hawaii’s Haleakala volcano. The new telescope will complement a fleet of observatories in space to paint an ever-clearer picture of the most important star in our sky.
Our scientific picture of the sun dates all the way back to Galileo. The father of modern astronomy is most famous for upending the cosmic order through his observations of the other planets. But he was also the first (or maybe second) European, in 1610, to observe the sun through a telescope. His student Benedetto Castelli figured out how to project a telescope image of the sun onto a wall in a dark room, enabling observations without frying the observer’s eyes. Galileo’s meticulous drawings based on these camera-obscura views are our earliest record of sunspots. Sunspots, in turn, were the first major evidence that the sun is hardly the passive disk most of us take for granted. Today we have this video, surely one of the most breathtaking livestreams on the internet, showing a churning and dynamic orb, captured by NASA’s Solar Dynamics Observatory.