Aurora Borealis is naturally occurred light display in sky during night in polar region.
The aurora borealis is also known as northern polar lights, as it is only visible in the North sky from the Northern Hemisphere.The Aurora Borealis most often visible in the months of September, October, March and April.
The reason behind the formation of Aurora Borealis is substorms in space. ULCA space scientists find the reason that triggers substorms in space lead to massive release of energy that creates Aurora Borealis.
To date, there are two competing theories, which explain the beginning of substorms in space.
The first theory explains that trigger happens relatively closer to earth, about one-sixth distance to moon. This theory stated that large currents in the space are made up of charged ions and electrons known as plasma are suddenly released by an explosive instability. The plasma moves towards earth due to disruption of space current which begins of the substorms.
Another theory stated that the trigger occurs at one-third distance to moon. This theory involves another process. According to this theory, due to storage of energy from the sun, two magnetic field lines come closer two each other and reached a critical limit, At this point magnetic field lines reconnect, causing magnetic energy to be transformed into kinetic energy and heat. This released energy causes plasma to accelerate, producing accelerated electrons which lighting up Aurora Borealis.
According to Vassilis Angelopoulos, a UCLA professor of Earth and space sciences and principal investigator of the NASA-funded mission known as THEMIS (Time History of Events and Macroscale Interactions during Substorms) the magnetic reconnection is the trigger.
According to him, reconnection results in a slingshot acceleration of waves and plasma along magnetic field lines, which cause the spectacular brightening of the aurora borealis, also known as the northern lights.
THEMIS has five satellites with electric, magnetic, ion and electron detectors and placed in carefully chosen orbits around the Earth and an array of 20 ground observatories with automated, all-sky cameras located in the northern U.S. and Canada that catch substorms as they happen.
