An unusual solar flare observed by a NASA space observatory on Tuesday could cause some disruptions to satellite communications and power on Earth over the next day or so, officials said.

The potent blast from the Sun unleashed a firestorm of radiation on a level not witnessed since 2006, and will likely lead to moderate geomagnetic storm activity by Wednesday, according to the National Weather Service.

"This one was rather dramatic," said Bill Murtagh, program coordinator at the NWS's Space Weather Prediction Center, describing the M-2 (medium-sized) solar flare that peaked at 1:41 am Eastern time in the United States, or 0541 GMT.

"We saw the initial flare occurring and it wasn't that big but then the eruption associated with it -- we got energy particle radiation flowing in and we got a big coronal mass injection," he said.

"You can see all the materials blasting up from the Sun so it is quite fantastic to look at."

NASA's solar dynamics observatory, which launched last year and provided the high-definition pictures and video of the event, described it as "visually spectacular," but noted that since the eruption was not pointed directly at Earth, the effects were expected to remain "fairly small."

"The large cloud of particles mushroomed up and fell back down looking as if it covered an area of almost half the solar surface," said a NASA statement.

Murtagh said space weather analysts were watching closely to see whether the event would cause any collision of magnetic fields between the Sun and Earth, some 93 million miles (150 million kilometers) apart.

"Part of our job here is to monitor and determine whether it is Earth-directed because essentially that material that is blasting out is gas with magnetic field combined," he told AFP.

"In a day or so from now we are expecting some of that material to impact us here on Earth and create a geomagnetic storm," he said.