A sunspot recently put out a surprising X-class flare, one of the strongest solar flares our home star is capable of producing. The enormous explosion created a rarely seen “solar tsunami” on the sun’s surface and triggered an intense burst of radiation that caused radio blackouts on Earth.
And in a rare recording, a radio astronomer managed to capture the eerie sounds of the solar storm slamming into our planet’s atmosphere.
The X-class flare occurred on February 17th. spaceweather.com (opens in new tab) reported. It was spewed out by a sunspot designated AR3229 that had only recently formed. National Oceanic and Atmospheric Administration (NOAA) solar storm forecasters had predicted a low probability of an X-class flare that day, but believed the threat would instead come from the much larger sunspot AR3226. As a result, astronomers were caught off guard by the stellar explosion, which had a magnitude of 2.2, according to Spaceweather.com. (Solar Flare classes include A, B, C, M, and X, with each class being at least 10 times more powerful than the previous one. Each class is divided into separate categories numbered 1 through 9 — with the exception of the X class flares , which have no defined upper limit.)
The eruption triggered a rare type of shock wave known as a solar tsunami, which spread across the Sun’s visible surface, or photosphere, according to Spaceweather.com. A solar tsunami, also referred to by scientists as a fast-mode magnetohydrodynamic wave, is essentially “a giant wave of hot plasma” moving through the photosphere at up to 901,000 km/h (560,000 mph) and reaching altitudes of about 62,150 miles ( 62,150 miles) can reach. 100,000 km), acc NASA (opens in new tab).
Related: 10 solar storms that blew our minds in 2022
The flare also emitted a Type II solar radio burst — a stream of mostly ultraviolet and X-ray radiation — that struck Earth shortly after the flare erupted. The radiation ionized the upper atmosphere and caused minor radio blackouts in parts of America for about an hour, according to Spaceweather.com. (There are five categories of solar radio surges. Type I is the weakest and Type V is the strongest and can cause widespread and prolonged blackouts.)
Amateur radio astronomer and citizen scientist Thomas Ashcraft (opens in new tab)who lives in New Mexico managed to capture a rare one audio recording (opens in new tab) of the radio burst that hit the earth. Composed of static electricity generated by radiation hitting the atmosphere, the eerie sound was picked up rather accidentally.
The eerie sound clip of the radio burst hitting the earth. (Image credit: Thomas Ashcraft)
“The Sun was directly in the beam of my radio telescope when the flare occurred,” Ashcraft said spaceweather.com (opens in new tab). This allowed him to capture the “full force” of the radio burst, which would not have been possible had his telescope not already been pointed at the sun, he added.
X-class flares seem to be more common. On January 3rd, a potential X-class flare, the first of the year, erupted from a massive sunspot hidden on the far side of the sun. Since then, the sun has spat out another five confirmed X-class flares, including the most recent one. In comparison, there were only seven X-Class flares in all of 2022 SpaceWeatherLive.com (opens in new tab).
The surge in X-class flares is likely the result of the Sun entering a more vigorous phase of its 11-year solar cycle, which should peak in 2025. The increase in activity has also led to this more sunspots to appear on the sun’s photosphere.