Northern Lights fanatics have been left "bewildered" after a child blue-coloured spiral resembling a galaxy appeared amid the aroura within the skies of Alaska.

Although it may need appeared just like the sudden look of a portal, or the beginnings of an alien invasion, the sky spiral was brought on by extra gas launched from a SpaceX rocket that launched from California about three hours earlier.

"Sometimes rockets have fuel that needs to be jettisoned (dropped from the aircraft). When they do that at high altitudes, that fuel turns into ice," area physicist Don Hampton, a analysis affiliate professor on the University of Alaska Fairbanks Geophysical Institute defined.

"And if it happens to be in the sunlight, when you're in the darkness on the ground, you can see it as a sort of big cloud, and sometimes it's swirly."

The rocket took off from Vandenberg Space Force Base in California on Friday 14 April.

Such a uncommon incidence, it was no shock the looks of the swirl prompted an "internet storm" after being caught on time-lapse on the Geophysical Institute's all-sky digicam.

Professional photographer Todd Salat was additionally left amazed by - what he known as - the "really cool looking spiral thing".

"This all happened as it passed over Alaska during a beautiful aurora display, stunning many night-watchers including myself," he stated.

"Trust me, at first, I was totally bewildered. I now know it can be explained with rocket science, but during and immediately after the experience, I thoroughly enjoyed the mysterious feeling of the unknown."

It was the timing of the gas dump and the very fact it was a polar launch which made the blue spiral seen over components of Alaska.

It comes as this week, Elon Musk's SpaceX will make a second try at launching the world's strongest rocket system after the primary was scrapped after it suffered a glitch moments earlier than take-off.

The launch will happen from southern Texas between 8.28am native time (2.28pm within the UK) and 9.30am (3.30pm within the UK), on Thursday 20 April.

Content Source: information.sky.com