(Photo: Wikimedia Commons/NASA Goddard Space Flight Center)
Sun's Giant Unstable Sunspot Unleashes Powerful Solar Flare That Causes Radio Blackouts Across Australia, Southeast Asia

A powerful solar flare erupted earlier this week. It was so strong that it caused shortwave radio blackouts.

Sun Unleashes Powerful Solar Flare

A massive unstable sunspot erupted, sending a hot plasma plume hurtling through the sun's atmosphere at 400 km/s (900,000 mph) and causing radio blackouts on Earth.

On Monday (Feb 5), at 8:30 p.m. EST (1030 GMT on Feb 6), the long-duration solar flare from the sunspot region AR3575 began. The eruption peaked at 10:15 EST (0315 GMT on the same day), as reported by solar physicist Keith Strong on X, formerly Twitter.

A coronal mass ejection (CME), or significant outburst of plasma and magnetic field from the sun, was also emitted during the eruption.

When a CME strikes the planet, it can disrupt the magnetic field, resulting in "geomagnetic storms" that are exciting for those who pursue auroras but problematic for satellites orbiting the planet. Strong said that even while it is improbable that this specific CME will hit Earth because of how far south on the sun the explosion is located, it might just pass right under us.

The powerful X-ray pulse and intense UV radiation that the M-class solar flare sent hurtling toward Earth when the explosion resulted in widespread radio blackouts. The outburst caused shortwave radio blackouts on the part of Earth that was exposed to sunlight.

The radiation, traveling at the speed of light, arrived on Earth in less than eight minutes and ionized the thermosphere, the top layer of the atmosphere.

According to Spaceweather.com, there were shortwave blackouts in Australia and Southeast Asia, and seafarers and ham radio operators in the region may have detected a loss of signal at frequencies below 30 MHz for up to an hour after the flare's peak.

ALSO READ: Cannibal Coronal Mass Ejection From Sun Could Cause Days-Long Radio Blackout: Report

What Is a Solar Flare?

Solar Flare is a strong outburst of radiation caused by the sunspot-related release of magnetic energy. The biggest explosions in our solar system are called flares.

They can linger for minutes or hours and are observed as bright patches of the sun. When a solar flare occurs, we can usually identify it by the photons (or light) it produces, which can be any wavelength in the spectrum. We mostly use optical light and X-rays to monitor flares. Particles (protons, electrons, and heavier particles) are also accelerated at flare sites.

They are divided into lettered groups according to their power, with the X-class being the strongest. M-class solar flares are ten times smaller than X-class, C-class, B-class, and A-class flares, which are too weak to have a noticeable impact on Earth.

The numbers ranging from 1 to 10 (and higher for X-class flares) indicate the relative strength of each class of flare. The National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center reports that the most recent flare had a magnitude of M4.2.

Last month, at least two solar flares, categorized as M-class, hit Earth. The solar storms interfered with communications across the Pacific Ocean.

According to Dr. Tamitha Skov, one of the solar flares was "the largest we have seen in weeks." It was so strong that it resulted in brief radio blackouts that affected Australia and the Asia-Pacific region.

RELATED ARTICLE: Sunspot Releases Huge X-Class Solar Flare; Cannibal Coronal Mass Ejection Brings Northern Lights in Places They Are Not Typically Seen

Check out more news and information on Solar Flares in Science Times.