Our Sun's Corona Unfurled

This clever image is actually two solar eclipses stacked atop one another. The bottom half of the image shows the sun's corona -- its wispy, dramatic outer atmosphere -- during the a 2017 total solar eclipse, and top half shows a 2023 total solar eclipse. (Image credit: P. Ward; via APOD) Read the full article

Kelvin-Helmholtz and the Sun

Kelvin-Helmholtz instabilities (KHI) are a favorite among fluid dynamicists. They resemble the curls of a breaking ocean wave -- not a coincidence, since KHI create those ocean waves to begin with -- and show up in picturesque clouds, Martian lava coils, and Jovian cloud bands. (Image credit: NASA/Johns Hopkins APL/NRL/Guillermo Stenborg and Evangelos Paouris; research credit: E. Paouris et al.; via Gizmodo) Read the full article

Observations of many solar phenomena have only become accessible to humans relatively recently with the advent of satellites. Prior to that, it simply wasn’t feasible to observe dynamics in the sun’s atmosphere, like solar prominences or coronal mass ejections -- the sun was simply too bright to see them -- except during the occasional total solar eclipse! 

In the 1970s, scientists identified massive bursts of solar plasma as coronal mass ejections. These solar storms are responsible for so-called space weather and, when directed toward Earth, can pose a hazard to technologies on the ground and astronauts in orbit. Scientists initially thought this was the first time such storms had been observed, but they later recognized that photographs and sketches of an 1860 total eclipse revealed that humanity had seen a coronal mass ejection more than 100 years before! Check out the NASA video below for the full story. You can also learn about some of the science that will be going on in today’s eclipse. And, for those in the U.S. today, have a fun and safe time viewing the ecliipse!  (Image credit:  S. Habbal, M. Druckmüller and P. Aniol, source; video credit: NASA Goddard)