The red rainbow appears throughout Europe

If aiming for superior cameras to the sky these days, Europeans can admire the countless red rainbows in the sky.

People can hardly observe the red rainbow with their naked eyes. (Photo: Livescience)

When high-charged particles from the sun rush into the earth's atmosphere, they cause geomagnetic storms.Geomagnetic storms cause disturbance in the magnetosphere - the air layer that electromagnetic fields dominate.The most obvious consequences of geomagnetic storms are huge and bright aurorae on the two polar regions of the earth.In addition, they also cause faint red rainbows on the ionosphere (regions containing many ions, stretching from a height of 85 to 600km from the ground) of the atmosphere.

Those loops emit so weak red light that humans are almost invisible to the eye. They appear at low latitudes, while aurora occurs at high latitudes.

Light pollution is one of the reasons people can't see the red rainbow. But recently the ASIAGO (All-Sky Imaging Air-Glow) observatory in Italy has used cameras with extremely sensitive sensors and fisheye lenses to observe the red and blurred aurora in the European sky, Livescience said.

A group of international experts observed the sky with ASIAGO observatory cameras when a storm hit the Earth in 2011. After comparing their data with satellite images and devices on the ground, they concluded that the red rainbow covered most of Europe - stretching from Ireland in the west to Belarus in the east.