World’s largest solar telescope takes its first shot

This new close-up of the turbulent boiling plasma of the solar surface is the debut image of the largest telescope ever built for staring at the Sun. Sporting a 4-meter-wide mirror—twice the size of any existing solar scope—and a vantage point 3000 meters up on the summit of Haleakala on the Hawaiian island of Maui—the Daniel K. Inouye Solar Telescope (DKIST) will reveal unprecedented detail of processes that channel energy from the Sun’s interior into its atmosphere, the corona.

Researchers hope that by zooming in on cell-like structures like those shown above—each about the size of Texas—they can learn what causes the Sun to launch powerful flares out into space, potentially causing damage to Earth’s satellites, power grids, and communications. Such information could help scientists give warnings of such events days rather than minutes ahead.

DKIST researchers also hope to finally resolve nagging solar mysteries such as: Why is the corona—at more than 1 million degrees C—so much hotter than the Sun’s surface, and what launches the solar wind out into space? The DKIST will be aided in this by NASA’s Parker Solar Probe, launched in 2018 to dip into and sample the Sun’s atmosphere, and the European Space Agency’s Solar Orbiter, launching next month to survey the Sun at high latitudes.

The DKIST requires powerful cooling systems to dispel the 13 kilowatts of heat gathered by its main mirror. It also employs deformable optics to compensate for turbulence in the atmosphere which can blur its view. After this first light image, the DKIST will undergo 6 months of commissioning and will then be ready to start work, just as the first sunspots of the latest solar cycle start to build toward a maximum.