In a groundbreaking achievement, scientists have captured the most detailed images yet of “raindrops” on the Sun — streams of cooled plasma falling back toward the solar surface — using a high-powered ground-based telescope in California.
These vivid, colourised images showcase massive plasma arches and fine, thread-like structures in the Sun’s outer atmosphere, or corona, offering an unparalleled view into its turbulent dynamics.
This rare phenomenon, called coronal rain, occurs when superheated plasma in the corona cools, condenses, and cascades along magnetic field lines back to the Sun’s surface. These descending plasma strands, along with large looping prominences, are part of the intricate solar structures newly observed.
Captured in hydrogen-alpha light and artificially tinted in pink, the images were taken using advanced time-lapse technology to counteract distortion from Earth’s atmosphere. The research, led by the U.S. National Science Foundation’s National Solar Observatory and the New Jersey Institute of Technology (NJIT), was published this week in Nature.
“These are the most detailed observations to date, showing features we’ve never seen before — and some that we still don’t fully understand,” said Vasyl Yurchyshyn, NJIT research professor and co-author of the study.
The visuals were obtained using the 1.6-meter Goode Solar Telescope at the Big Bear Solar Observatory (BBSO) in California. Central to this success is a cutting-edge adaptive optics system named Cona, recently installed at BBSO. It uses a laser and a deformable mirror that adjusts 2,200 times per second to correct atmospheric blurring in real time.
“Cona is like a supercharged autofocus for the sky,” said BBSO’s chief observer, Nicolas Gorceix. Thanks to Cona, scientists can now resolve solar features as small as 63 kilometres (39 miles), compared to previous limits of about 1,000 kilometres (620 miles).
The Sun’s corona — Latin for “crown” — remains one of the greatest mysteries in solar science. Though it is less dense than the Sun’s surface (the photosphere), it is vastly hotter, reaching temperatures of several hundred thousand degrees — a phenomenon that continues to puzzle physicists. The corona is also the source of the solar wind, a continuous stream of charged particles that can interact with Earth’s magnetic field, sparking geomagnetic storms and auroras.
Following its success at BBSO, the Cona system is now being deployed at the Daniel K. Inouye Solar Telescope in Maui, Hawaii. With its massive 4-meter aperture, it is the largest solar telescope in the world and is expected to unlock even deeper insights into the Sun’s complex and fiery outer layers.
