Astronomers have observed that our Sun could be a potential threat to human civilization due to a phenomenon where the Sun ejects large bursts of energy called a “superflare.”
Superflares are the extreme versions of a typical solar flare — a sudden flash of increased brightness of the Sun and usually observed near its surface and close to a sunspot group. Powerful flares are often, but not always, accompanied by a coronal mass ejection. Even the most potent flares are barely detectable in the total solar irradiance.
However, unlike the typical solar flare, superflares are much stronger and powerful. Astronomers warn that a superflare could burst energy from its surface that could be seen light years away that could harmfully affect life on Earth.
Initially, scientists believed that superflares were only limited to be an occurrence in younger stars. However, Yuta Notsu and his team of researchers published their latest study rejecting that initial assumption and discussed otherwise in The Astrophysical Journal.
The study indicated that superflares were a natural and frequent occurring phenomenon on younger stars due to its small size and high energy. These younger stars would often burst large amounts of energy. Moreover, it was then believed that as these stars aged and became suns, superflares would incrementally decrease and eventually stop.
“When our Sun was young, it was very active because it rotated very fast and probably generated more powerful flares,” said Notsu in Boulder. “But we didn’t know if such large flares occur on the modern sun with very low frequency.”
However, a discovery from the results provided by the Kepler Space Telescope, a NASA spacecraft from 2009, found something odd about the stars it was observing. In rare events, the light from distant stars seemed to get suddenly, and momentarily, brighter.
Notsu explained that normal-sized flares are frequent on the sun. But what the Kepler data was showing seemed to be much bigger, on the order of hundreds to thousands of times more powerful than the most giant flare ever recorded with modern instruments on Earth.
The results should be a wake-up call for life on our planet, said Notsu during a visit at the University of Colorado Boulder.
If a superflare erupted from the sun, he said, Earth would likely sit in the path of a wave of high-energy radiation. Such a blast could disrupt electronics across the globe, causing widespread blackouts, and shorting out communication satellites in orbit.
This could be a massive threat for life on Earth, given that most of society is contingent along with the dependency on technological devices. Moreover, Notsu does not only refer to smartphones and Wi-Fi connectivity. Instead, a single wave of such superflares could cause catastrophic events on Earth.
“If a superflare occurred 1,000 years ago, it was probably no big problem. People may have seen a large aurora,” Notsu said. “Now, it’s a much bigger problem because of our electronics.”
Primarily, orbiting satellites would first be affected and render them useless—making all communication devices on Earth, including cellular phones, tracking services, GPS, radios, etc., to stop functioning. Moreover, all electronic-dependent technology would also stop working. This could mean aircraft are crashing all over the place, hospitals without operating equipment, or even plumbing and electric services become useless.
To make matters worse, researchers are also in the dark with regards to information about superflares. Currently, researchers don’t have an exact explanation of why superflares occur. Moreover, they cannot predict when a superflare could exactly arise, making it impossible to prevent and prepare for such situations.
To understand more, Notsu’s team ran new spectroscopic observations with the Kepler data, data from the European Space Agency’s Gaia spacecraft and the Apache Point Observatory in New Mexico.
Over a series of studies, the group used those instruments to narrow down a list of superflares that had come from 43 stars that resembled our sun. The researchers then subjected those rare events to a rigorous statistical analysis.
The team writes: “We need more studies to clarify the properties of superflare stars on Sun-like stars and to answer the important question, ‘Can our Sun have superflares?'” Also, “the number of old, slowly rotating Sun-like superflare stars [observed is] now very small, and the current statistical discussions are not enough.”
Fortunately, the team also told that superflares for older stars or Suns may not occur as frequent compared to younger stars. “Our study shows that superflares are rare events,” said Notsu. “But there is some possibility that we could experience such an event in the next 100 years or so.”