Mersey Reporter - #Merseybites #News

OVER the next few days you might get to see this stunning light display over Merseyside and West Lancashire if you missed it last night. Many of us might have missed it last night, as this time it just looked to the naked eye as a white misty cloud, but when photographed all the colours could be seen.

This dazzling display happened after a series of solar flares and coronal mass ejections, (giant explosions on the surface of the Sun) sent streams of energetic particles (solar wind) into space. They then headed our way and interacted with Earth's magnetic, to deliver the atmospheric effect.

The light happens when the ejected particles get trapped in the magnetic field. When they hit the Earth's upper atmosphere, they excite nitrogen and oxygen molecules and release photons of light, creating the aurora.

This time we are told that the source of the solar storm was a cluster of sunspots on the Sun's surface. These spots are estimated to be around 17 times the diameter of the Earth.

It's frequently possible to see the Aurora Borealis from the Northern parts of the UK, and you can get alerts when this notoriously unpredictable event might take place.

There have been more occasions in the last year to see the Aurora, but this year, and over next year, experts predict we will see even more opportunities like this until the solar activity decreases over the following 11 years. That's because the Sun is reaching the peak of activities, called the:- "solar maximum" of its 22/25 year cycle.

If you want to capture this magical light display please remember that the luminous colours you see on photographs are often much fainter to the naked eye and are easily washed out by light pollution or a bright Moon. Often, like last night, the effect can appear white to the human eye, so take a photo to see if any colours are visible. If you want to photograph it, use a SLR camera on a heavy, strong tripod. Set the exposure length between:- 10 and 30 seconds and an ISO of around 1600. Set to infinity and turn off auto-focus and exposure functions. But remember, it might not work with mobile phones. To escape manmade light pollution, you might want to consider searching the website:- DarkSky.Org for certified international dark sky places around the world. To increase your chances we suggest you follow AuroraWatchNet on social media or use Lancaster University's free Android and iOS (iPhone, iPad) AuroraWatch API but only if local conditions are good.

If you want to know what gases in the atmosphere produce the colours when they become excited, these are the most common. The pure green and greenish yellow colours are the results of the excitation of oxygen, at around 150 miles up in our atmosphere. The stunning purple or violet colours are from nitrogen at an altitude of above 60 miles, and nitrogen also emits blue and red light when up to 60 miles into our atmosphere.

Fun fact... The last time a solar storm of this magnitude reached Earth was in October 2003. Also, did you know you can get Black Aurora? This effect results in black bands within the Aurora, which appear to have substance. The effect blocks out starlight and is most likely the result of electric fields within the upper atmosphere that prevent electrons from interacting with gases!