The world’s largest solar telescope on top of the Haleakala volcano in Hawaii has used a new instrument that took 15 years to build to produce a spectacular first image of the sun.
The new test image, above, reveals a cluster of sunspots covering 241 million square miles of the sun’s surface, with each pixel representing 6.2 miles (10 kilometers), though the new instrument won’t be used regularly for science until next year. It’s hoped that it will help solar physicists uncover the underlying physics of the sun and how it drives space weather — which brings northern lights but also threatens infrastructure on Earth, ages satellites and can even harm astronauts.
Sunspots Explained
Magnetic disturbances on the sun’s surface that can be as big as Earth — as is the case here — sunspots are critical to solar scientists. Solar flares and coronal mass ejections originate in sunspots. Solar flares are intense blasts of radiation that travel at light speed, while CMEs are vast clouds of charged particles that travel more slowly but are a major cause of geomagnetic storms on Earth — which often spark displays of the northern and southern lights.
What The New Instrument Can Do
This new image comes from an instrument called the Visible Tunable Filter, which has recently been installed on the U.S. National Science Foundation’s Daniel K. Inouye Solar Telescope on Haleakala. The largest of its type, the VTF captures sunlight signals over a narrow range of frequencies, allowing it to map specific phenomena — such as magnetic fields, solar flares and plasma — at new levels of detail. It can scan different wavelengths and take hundreds of images a second using three cameras, combining the data to produce 3D views of the sun. The VTF was built by scientists at the Institute for Solar Physics in Freiburg, Germany.
Why Scientists Need To Study The Sun
Solar scientists need to understand what causes geomagnetic disturbances on Earth so they can predict them. “When powerful solar storms hit Earth, they impact critical infrastructure across the globe and in space,” said Carrie Black, NSF program director for the NSF National Solar Observatory. “High-resolution observations of the sun are necessary to improve predictions of such damaging storms.”
Solar Maximum
It just so happens that VTF is being debuted just as the sun reaches “solar maximum,” the peak of the 11-year solar cycle when its magnetic activity intensifies. It’s thought that the solar maximum occurred in October 2024, according to scientists at NOAA and NASA, though the tail of the peak can often bring with it intense magnetic activity.
Sunspots on the solar surface — which can be seen by anyone using a pair of solar eclipse glasses — are counted each day by solar scientists, with the number of sunspots indicating how magnetically active the sun is.
New Era In Solar Observation
It’s hoped that that with the VTF, the Inouye Solar Telescope will be able to precisely study the regions of the sun where solar flares and CMEs come from, and allow them to unpick the complex interaction of hot plasma flows and changing magnetic fields. “VTF enables images of unprecedented quality and thus heralds a new era in ground-based solar observation,” said Sami K. Solanki, director at the Max Planck Institute for Solar System Research in Göttingen,Germany.
Wishing you clear skies and wide eyes.
