Northern Lights - ScienceNerds

Northern Lights - A breathtaking display of particle physics in action

Northern Lights

The Northern Lights are so beautiful and they've understandably inspired tons of myths over the years such as the Vikings thought that were a bridge to Asgard where Thor and some other gods live and some Norse legend says that the light reflected off the shields of Valkyrie then people in Finland thought it was the Archangel Michael john Travolta fighting the devil named Beelzebub, the problem is those are wrong wrong wrong they're all wrong it was actually Galileo Galilei the famous early astronomer Andrew Cantor of science who given the Latin name aurora borealis which is called as dawn of the north.

until a scientist from Norwegian named Kristian Birkeland in 1896 figured out what causes the Northern Lights to see in the centre of the earth you will find hot molten iron just rolling around under tremendous gravitational pressure and this roiling effect of the molten iron creates magnetic fields that shootout from the centre of the earth through the crust and into the space around the planet that forms what's called the magnetosphere.

Earth's magnetic field

A good thing is that we have it because we are constantly being bombarded by charged particles emerging from the Sun so hot that the matter exists in the fourth state of matter there's gas-liquid-solid and then plasma and in plasma ions which are positively charged atoms and electrons just float freely around one another and these particles have such a high energy charge that they can escape the massive gravitational field over the Sun and barrel toward the Earth such as something around a million miles per hour like a shotgun blast full of solar hate that's known as the solar wind.

when these particles encounter with our magnetosphere most particles bounce harmlessly off the saved but some of them managed to get through at the places where the magnetosphere is weakest at the North and South Poles follow me when the electrons that make it through our magnetosphere and almost in our atmosphere kills oxygen and nitrogen the electrons transfer energy to these particles & set them to excited states to quiet back down the oxygen and the nitrogen needs to shoot off a portion of this energy which they do in the form of tiny packets of light called photons beautiful beautiful photons depending on where in the atmosphere the electrons interact with the oxygen or the nitrogen different colours will be produced.

Solar wind deflection by the magnetic field

Aurora illustration

Oxygen up to about a hundred and fifty miles will produce a nice yellow-green colour when electrons bombard it above that it emits a nice red colour and nitrogen after travelling about sixty miles into the atmosphere produces blue and all these colours mix up together forming beautiful glowing pinks and purples and whites it's like Miami Beach up there.

Every second a huge amount(million tons) of matter blasted from the Sun at a velocity of million miles per hour and it's on a collision course with earth but don't worry its just the opening of a new Michael Bay movie this the journey of the polar lights the northern and southern lights also known as the aurora borealis and Aurora Australis occur when highly-energetic particles from the Sun collide with neutral atoms in the atmosphere, the energy is emitted from this crash produces a spectacle of light that mankind has marveled at for a considerable length of time however molecule's excursion isn't that basic as withdrawing Sun and landing at earth like any cross country excursion.

Solar wind illustration

The sun's atmosphere and is one among the most well liked regions, it's intense heat causes the sun's hydrogen and helium atoms to vibrate and shake off protons and electrons and these free protons and electrons move very fast to be contained by the Sun's gravity and grouped as plasma an electrically charged gas they travel faraway from the Sun as referred to as the solar radiation , however, the earth's magnetic flux prevents the solar radiation from entering straight into the earth by fixing a detour the magnetosphere is made by the Earth's magnetic shields protecting our planet from the solar winds by reflecting back particles round the earth their opportunity to continue the journey right down to the atmosphere comes when the magnet spheres overwhelmed by a replacement wave of travellers this event is coronal mass ejection, it overpowers the magnetosphere and creates a perturbation the heavy storm stresses the magnetosphere until it suddenly snaps back like an overstretched rubber band flinging a number of the detoured particles towards Earth there tracking band of the magnetic flux lags them right down to the Aurora ovals which are the locations of the northern and aurora australis after travelling 93million miles across the galaxy the sun's particles finally produce their dazzling display with the assistance of some friends 22 hundred miles above the surface, the electrons and protons meet with oxygen and nitrogen atom sand they sure are happy to ascertain one another the sun's particles high-five the atoms giving their energy to the world and neutral oxygen and nitrogen atoms when the atoms within the atmosphere are contacted by the particles they get excited and emit photons are small bursts of energy within the sort of light the colors that appear within the sky depend upon the wavelength of the atom-photon excited oxygen atoms cause the green and red colours whereas excited nitrogen atoms produce blue and red colours the gathering of those interactions is what creates the northern and aurora australis the polar lights are seen in clear nights in regions on the brink of north and south poles nighttime is current because the aurora is far dimmer than sunlight and can't be seen in the current day time.

Aurora Colours and causes: