The largest solar storm to hit our planet for more than 20 years could disrupt communications and satellite navigation systems, the British Geological Survey has warned.

The organisation has upgraded its geomagnetic forecast to the highest intensity level amid what has been dubbed a “cannibal storm”.

Current predictions suggest a second storm, feeding off one from earlier in the week, could have further effects on space and ground-based technologies, the BGS said.

Early indications such as ground measurements of solar energetic particles were some of the largest recorded since 2005, it said.

NASA has postponed a space launch because of the “highly elevated solar activity”.

The mission was to carry two Mars-bound NASA spacecraft.

“Nasa is postponing launch until space weather conditions improve,”space tech company Blue Origin said.

“We are currently assessing opportunities to establish our next launch window based on forecasted space weather and range availability.”

The solar activity meant the northern lights might be visible across parts of the northern hemisphere on Wednesday night, following a similar alert for the southern lights in the southern hemisphere.

Britain’s Met Office said the solar storm was a result of the sun going through an active phase experiencing coronal mass ejections, which are large expulsions that send solar particles towards the Earth.

As these particles interact with the Earth’s atmosphere, they form a dazzling light display, commonly known as the northern lights or southern lights.

“Multiple coronal mass ejections have reached Earth in recent days,” Met Office space weather manager Krista Hammond said.

“This event is likely to be of a similar magnitude to the one in May 2024, which brought auroras across much of England and Wales.”

-AAP