NSF’s Daniel K. Inouye Solar Telescope is key to gaining a better understanding our nearest star


In March 1989, astronomers could only watch as a vast cloud of electrically charged particles and magnetic fields erupted from the sun, eventually slamming into Earth’s magnetic fields. Satellites in orbit went silent, or worse yet, lost control, as high-energy particles from the “solar storm” blasted their electronics. On Earth, the intense magnetic field caused the entire power grid of the Canadian province of Quebec to go offline for nine hours, trapping people in elevators, plunging office towers into darkness and closing the airport.

That was more than three decades ago, and yet the sun – our nearest star – remains as mysterious and chaotic as ever.

As these recently unveiled first images demonstrate however, NSF’s Daniel K. Inouye Solar Telescope is about to usher in a new era of solar science and deepen our understanding of the sun and its impacts on our planet.

Built by NSF’s National Solar Observatory and managed by AURA, the Inouye Solar Telescope combines a 13-foot (4-meter) mirror — the world’s largest for a solar telescope — with unparalleled viewing conditions at the 10,000-foot Haleakala summit on Hawaii’s Island of Maui. With the largest aperture of any solar telescope, its unique design, and state-of-the-art instrumentation, the Inouye Solar Telescope — for the first time — will be able to perform the most challenging measurements of the sun.

The first images from NSF’s Inouye Solar Telescope show a close-up view of the sun’s surface, which can provide important details for scientists. Activity on the sun, known as space weather, can affect systems on Earth. Magnetic eruptions on the sun can impact air travel, disrupt satellite communications and bring down power grids, causing long-lasting blackouts and disabling technologies such as GPS.

The Inouye Solar Telescope provides unprecedented close-ups of the sun’s surface, but ultimately it will measure the sun’s corona – no total solar eclipse required. Previously, researchers had to wait for a total solar eclipse to block the sun to study its outer atmosphere, the corona, where solar storms begin. This 4-meter telescope and five cutting-edge tools will allow us to map the sun’s surface and its atmospheric magnetic fields, especially the inner corona.

The year 2020 will start us on the road towards clearer understanding of the sun. Because that’s where it all starts.  Forecasting changes won’t happen overnight, but this solar telescope will help build the knowledge bank that eventually informs space weather prediction on our own planet. This multi-pronged, multi-agency research infrastructure will build foundational knowledge of the sun to make that happen. And as technology improves, the ground-based Inouye Solar Telescope also will be able to upgrade to harness advances. For the time being, solar astronomers have this new tool to see our nearest star if not with perfect vision – the clearest, most detailed yet.