DKIST Observatory’s Most Powerful Solar Camera Now Live

Exploring the Sun With Close-Range Astronomy

Astronomy is a science often focused on very distant and alien celestial objects, from radiating pulsars and ominous black holes to abstract pictures of the background radiation emitted in the Big Bang. Sometimes, it is looking closer to home, studying the still not-so-well-understood nearby planets.

Source: ESO

Much less often do we consider how little we know about one very important star, our very own Sun. We still need to understand the cycles of activity it undergoes, as well as what it can reveal to us about other stars. As the closest star to Earth, it provides much more detailed and accurate data than any other star we can observe.

This is the task of the Daniel K. Inouye Solar Telescope (DKIST), a facility at Haleakala Observatory on the Hawaiian island of Maui, previously known as the Advanced Technology Solar Telescope (ATST).

DKIST recently went through a major upgrade of its imaging system, 10 years in the making. And it might unlock a deeper level of understanding of the Sun, as well as maybe warning about the danger of solar storms for our fragile human electric and electronic systems.

A Brief History of Solar Observations and Breakthroughs

Since the first discoveries of Sunspots in 1611, astronomers have progressively learned more about the Star around which Earth orbits.

For example, they learned that the Sunspot numbers, now known to reflect the magnetic activity of the Sun, oscillate around a cyclical pattern, but also that it can be interrupted for unknown reasons over decades.

Source: NASA

Further progress was made with the invention of spectroscopy in the 19^th century, a technique able to detect specific elements from the Sun’s light, revealing its atomic composition.

Source: NASA

It was in 1859 that we realized the Sun could affect Earth beyond illumination and weather patterns, with the Carrington Event. Named after Richard Carrington, an English astronomer who observed a massive solar storm; 17 hours later, it would result in telegraph systems across the Western world failing and catching fire, in some cases giving their operators electric shocks.

This strong effect on electrical systems was due to the geomagnetic storm coming together with an enormous coronal mass ejection, in which charged particles from the Sun are ejected in an explosive burst, creating powerful electric currents and northern lights.

Source: Ars Technica

The magnetic nature of the Sun would be confirmed in 1908 by American astronomer George Ellery Hale, who found that sunspots have magnetic fields over a thousand times stronger than Earth’s.

In 1931, French astronomer Bernard Lyot invented the coronagraph, a telescope that artificially mimics a solar eclipse by blocking out light from the Sun’s bright surface, allowing for better study of the Sun’s atmosphere.

In 1976, the Helios Mission became the first probe to come closer to the Sun than Mercury’s orbit, followed by the 2018 Parker probe traveling to “just” 3.8 million miles of the Sun at 430,000 miles per hour. In 2020, the European Space Agency (ESA) Solar Orbiter was launched into a polar orbit, taking the very first picture of the solar north and south poles.

Why Solar Astronomy Is Crucial for Earth and Space

From a purely intellectual point of view, a better understanding of the Sun can radically improve our understanding of the Universe by making it a lot clearer how this star in particular works, and by extension, any other star in the Universe. And by itself, this can be a good enough reason to promote this sort of scientific effort.

But this could also have a lot of practical results as well. As mankind becomes increasingly a space-faring civilization, notably thanks to super-heavy rockets like SpaceX’s Starship, a better understanding of the Sun’s activity can become crucial for future deep space missions to Mars or beyond, which could be dangerous in case of unexpected solar storms.

These solar storms could also be very disruptive on Earth if they are strong enough. Nothing indicates that the Carrington Event was an especially rare phenomenon. So as we depend on way more electrical systems than in the age of the telegraph, such a storm could wreak havoc on modern civilization. Properly understanding the Sun’s activity could help at least prepare, and also properly estimate the risks of such an event occurring again.

“When powerful solar storms hit Earth, they impact critical infrastructure across the globe and in space. High-resolution observations of the sun are necessary to improve predictions of such damaging storms.”

Carrie Black – NSF program director for the NSF National Solar Observatory.

Besides geomagnetic risks, changes in the Sun’s activity have been linked to radical changes in climate, notably the “mini-ice age” of the late 18^th century, when the River Seine in Paris froze. Properly predicting the Sun’s long-term cycle could strongly improve our climate model and help us better understand how the Sun could impact climate change, for good or for bad.

Lastly, this sort of project generally pushes forward the limits of science and engineering as we know it. It often results in developing new materials, new software, and overall new technologies that might find their way into other applications. For example, the CERN particle accelerator was instrumental in inventing the early Internet.

What Is the Daniel K. Inouye Solar Telescope (DKIST)?

The Daniel K. Inouye Solar Telescope is the world’s largest solar telescope with a 4-meter aperture, observing the Sun in visible to near-infrared wavelengths.

It is part of the National Solar Observatory (NSO), involves 1,000+ scientists, and 10 different telescopes.

These large dimensions allow the telescope to reach much greater image resolution. It also helps collect enough photons from the sun to perform accurate polarimetry measurements (more on that technique below).

Among other important abilities of the telescope is its ability to simultaneously detect near ultraviolet and infrared wavelengths, allowing for creating a 3D model of the solar atmosphere. It also captures images very quickly, so this model can capture the changing dynamics of the Sun’s atmosphere and indirectly measure its magnetic fields.

The telescope has been active since 2022 and is gradually being equipped with additional scientific instruments to analyze the sunlight it collects.

The site of Hawaii has been chosen thanks to the combination of many days of clear sky per year and low levels of air pollution in the middle of the Pacific Ocean.

Inside the DKIST Telescope: Components and Capabilities

The site of the telescope is a rather large complex, with supporting multi-level buildings tied to the observatory itself.