The Northern Lights are caused by the solar wind, which consists of charged particles emitted by the sun during solar flares and coronal mass ejections.
When these charged particles reach Earth, they interact with the planet's magnetosphere, a protective magnetic field that surrounds the Earth.
The particles are funneled towards the magnetic poles by Earth's magnetic field, which is why the auroras are most commonly seen near the Arctic and Antarctic circles.
As the solar particles collide with gases in the Earth's atmosphere, such as oxygen and nitrogen, energy is released in the form of light, creating the auroras.
The specific colors of the Northern Lights depend on the type of gas and its altitude. Oxygen emits green and red light, while nitrogen produces blue and purple hues.
Green auroras typically occur at altitudes of about 60 to 150 miles, while red auroras occur above 150 miles. Blue and purple auroras can be seen below 60 miles.
The area where the Northern Lights are visible is called the auroral oval, a ring-shaped zone centered around the magnetic poles. This oval shifts and changes shape with geomagnetic activity.
Increased solar activity, such as solar flares and coronal mass ejections, can cause geomagnetic storms, which intensify the auroras and expand their visibility to lower latitudes.
Scientists monitor space weather using satellites and ground-based observatories to predict auroral activity and provide real-time aurora forecasts.
Studying the Northern Lights helps scientists understand the dynamics of Earth's magnetosphere, the behavior of solar wind, and the broader aspects of space weather, which can impact satellite operations, GPS, and power grids on Earth.