From our vantage point on Earth, the sun is often a miraculous sight, shining brightly on clear days and bathing the sky in vivid color as it rises and sets. This week, astronomers released stunningly detailed images of the sun’s surface—revealing that up close, the star is pretty spectacular, too.
As Alexandra Witze reports for Nature, these are the first images taken with the National Science Foundation’s Daniel K. Inouye Solar Telescope, which sits atop Haleakala, a dormant volcano in Hawai‘i. The Inouye Solar Telescope is the most powerful solar telescope in the world, and according to the National Science Foundation (NSF), its images show the sun in “unprecedented” detail.
The celestial body looks like a bubbling expanse of golden kernels, which in fact represent plasma that covers the sun. The kernels—or “cell-like structures,” as the NSF puts it—are each about the size of Texas. Hot solar plasma rises up in the center of the cells and then cools, sinking down from the surface—“a process known as convection,” the NSF notes.
The sun is a constant swirl of violent activity, burning around 5 million tons of hydrogen fuel every second. That energy radiates into space, and the movement of the sun’s plasma “twists and tangles” solar magnetic fields, according to the NSF.
From 93 million miles away, we can’t see all this motion, but we sometimes feel its effects. For instance, coronal mass ejections from the sun shoot charged particles into space that can collide with the Earth’s atmosphere and disrupt satellites, telecommunications and navigation systems, and power grids. In 2017, a solar flare caused blackouts across a wide geographic area, including the Caribbean—where, in an unfortunate coincidence, Hurricane Irma was raging and emergency radio communications were knocked out.
Scientists hope that the Inouye Solar Telescope will help them gain a better understanding of “space weather,” a general term that refers to conditions on the sun, in the solar wind, and within Earth's magnetosphere, ionosphere and thermosphere, according to NASA. The standard notification time for space weather is currently 48 minutes; experts want to extend that period to 48 hours, allowing for more time to secure infrastructure and satellites.
“On Earth, we can predict if it is going to rain pretty much anywhere in the world very accurately, and space weather just isn’t there yet,” says Matt Mountain, president of the Association of Universities for Research in Astronomy, which manages the Inouye Solar Telescope. “Our predictions lag behind terrestrial weather by 50 years, if not more.”
The new telescope features a 13-foot mirror. More than seven miles of underground piping are required to cool the instrument as it collects solar heat. “The greater size of the mirror, abetted by adaptive optics that reduce atmospheric blurring, offers higher resolution,” explains Dennis Overbye of the New York Times. Engineers are still working to finish the telescope’s dome, according to Nature, and studies will begin “in earnest” this summer. With this powerful technology at their fingertips, scientists may be able to shed light on some of the sun’s more confounding secrets—like why the corona, or outer atmosphere of the sun, is millions of degrees hotter than its surface.
So while the new close-ups of the sun are fascinating, experts say the images represent just a tantalizing glimpse into the telescope’s capabilities.
“These first images are just the beginning,” claims David Boboltz, a program director in NSF’s Division of Astronomical Sciences. “The Inouye Solar Telescope will collect more information about our sun during the first five years of its lifetime than all the solar data gathered since Galileo first pointed a telescope at the sun in 1612.”