Powerful superflares could pose a threat to Earth

Saturn-like planet orbiting not 1 but 2 stars

Saturn-like planet orbiting not 1 but 2 stars

Astronomers probing the edges of the Milky Way have in recent years observed superflares - huge bursts of energy from stars that can be seen from hundreds of light years away.

'When our Sun was young, it was very active because it rotated very fast and probably generated more powerful flares, ' said astronomer Yuta Notsu, who is a visiting researcher at the University of Colorado Boulder.

It was long thought that these superflares only took place on young and active stars and that our sun-which is much older-would not be capable of producing them.

"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?'" the team writes.

If a superflare erupted from the sun, the Earth would likely sit in the path of a wave of high-energy radiation, researchers said.

Among the potential consequences, such an event could lead to blackouts all around the world, or cause satellites in orbit to malfunction-disabling communications technologies, global positioning systems and more.

The data used in the study was collected with the help of the Kepler space telescope which surveyed distant planets over eleven years.

The spacecraft launched in 2009, and its goal was to seek out planets circling stars that are very far from Earth.

Notsu explained that normal-sized flares are common on the Sun.

What Kepler had discovered are flares said to be hundreds or thousands of times more powerful than the largest solar flare ever recorded on Earth using modern instruments.

Younger stars produce the most superflares, the researchers found. "For the sun, it's once every few thousand years on average", Notsu said. Coronal mass ejections from the sun - or large plumes of charged particles - have caused issues with our infrastructure in the past, such as the extraordinary 1859 Carrington Event superstorm that affected telegraph communications.

That loose certainty is all we have for now, but it's imperative we try to refine our knowledge in the future - not just about the likelihood of a superflare emanating from the Sun, but also what might happen if it comes to pass.

The team of researchers employed data collected by the Gaia Spacecraft and the Apache Point Observatory in Mexico to verify their discoveries.

"The number of old, slowly rotating Sun-like superflare stars [observed] are now very small, and the current statistical discussions are not enough". But he said that it's a matter of when, not if.

"If a superflare occurred 1,000 years ago, it was probably no big problem".

According to him, people would have simply witnessed a particularly large aurora.

Dr Notsu hopes that the warning might give humanity time to prepare by developing shielding to protect electronics on the ground and in orbit from these bursts of stellar radiation.

"Now, it's a much bigger problem because of our electronics", he added.