Nasa warns of huge solar flares that could cause blackouts on Earth

A solar flare last week was so big it disrupted radio transmissions on Earth.

Nasa said the burst of energy was the biggest flare of 2025 so far, and there could be more to come, with the sun at the most active point of its eleven year cycle.

They warned: ‘Flares and solar eruptions can impact radio communications, electric power grids, navigation signals, and pose risks to spacecraft and astronauts.’

This latest flare on May 14 affected high frequency radio communications for ten minutes in the Middle East.

It was classed as X2.7, which means it is in the highest, ‘extreme’ category of solar flare – though the category is open ended, and the highest ever recorded was an estimated X45, during the ‘Halloween’ solar storms in 2003.

What we know about the blackout warning

The Met Office space weather prediction also says there is a risk of ‘minor radio blackouts’ throughout this week.

The idea of the sun interfering with our electrics and radio signals, as well as giving us sunburn, sounds dramatic but it isn’t unheard of.

In May last year, multiple coronal mass ejections led to a strong geomagnetic storm which massively impacted the US precision industry, which uses GPS to help improve crop yields and make farms more efficient.

The Met Office said there are seven sunspot regions currently facing Earth which could potentially impact us.

Yesterday, a ‘slow but large’ Coronal Mass Ejection (CME) was visible – the thing which can cause us to see the Northern Lights.

However, don’t go rushing for your camera, as this has been modelled as most likely missing Earth.

What is a solar flare?

Solar flares are powerful bursts of electromagnetic radiation from the Sun. They are are often associated with solar magnetic storms known as coronal mass ejections (CMEs).

‘These emissions of electromagnetic radiation travel at the speed of light and so reach the Earth about eight minutes after they have left the Sun.’

Meanwhile, CMEs can take anywhere between 15 hours and several days to reach Earth.