DEFINITION: Auroras, also known as northern lights (Aurora Borealis) and southern lights (Aurora Australis), are natural light displays characterized by bright, swirling curtains of various colors in the night sky.

COLORS: These lights can appear in a range of colors such as blue, red, yellow, green, and orange.

OCCURRENCE AND LOCATIONS:

• Northern Hemisphere: Aurora Borealis occurs near the North Pole and can be witnessed in regions like Ladakh, the United States, and the United Kingdom.
• Southern Hemisphere: Aurora Australis occurs near the South Pole and is observed in places like New Zealand and Australia.

CAUSES OF AURORAS:

• Solar Activity: Auroras are caused by activity on the surface of the Sun, including the continuous release of charged particles (electrons and protons) and magnetic fields known as the solar wind.
• Earth’s Magnetic Field: The Earth’s magnetic field deflects the solar wind, but some charged particles are trapped and travel down magnetic field lines to the poles.
• Interaction in Earth’s Atmosphere: When these particles interact with gases in the Earth’s upper atmosphere, they produce light flashes that create the auroras.
• Color Formation: Interaction with oxygen results in green light, while nitrogen produces shades of blue and purple.

EXPANSION TO LOWER LATITUDES:

• Solar Wind Strength: Auroras typically occur near the poles, but they can expand to lower latitudes during periods of intense solar activity.
• Geomagnetic Storms: Solar flares and coronal mass ejections (CMEs) can cause geomagnetic storms, disrupting the Earth’s magnetic field and allowing auroras to be visible in mid-latitudes.

RECENT ACTIVITY:

• Geomagnetic Storm: A recent geomagnetic storm caused by a CME hitting Earth led to visible auroras in various parts of the world.
• Impacts: Geomagnetic storms can affect GPS, radio and satellite communications, flight operations, power grids, and space exploration programs.