Prelims Focus 9th June 2026

Aurora Borealis in Indian Skies

In News: The Northern Lights (Aurora Borealis) were indeed expected to be visible in India on the night of June 8, 2026. 

• Auroras are occasionally visible in India’s extreme high-altitude regions, such as Ladakh, Kashmir, Arunachal Pradesh, and the upper Himalayas in Uttarakhand. These breathtaking celestial displays typically occur during strong geomagnetic storms, which push the auroral oval far past its usual polar limits. 

What is an Aurora?

• Definition: Auroras are natural, luminous light displays in the night sky. In the Northern Hemisphere, they are known as the Aurora Borealis (Northern Lights), and in the Southern Hemisphere, as the Aurora Australis (Southern Lights).
• Appearance: They manifest as shimmering, undulating curtains, arcs, or diffuse glows in various colors such as red, green, purple, and pink.

Mechanism of Formation

• Solar Wind and CMEs: The Sun continuously ejects a stream of highly energetic charged particles (mainly protons and electrons) known as the solar wind. During violent solar events, massive explosions called Coronal Mass Ejections (CMEs) release huge clouds of plasma and magnetic fields into interplanetary space.
• Interaction with Magnetosphere: As these particles approach Earth, they are funneled by the planet’s protective magnetic field (the magnetosphere) towards the magnetic poles.
• Excitation and Emission: Upon entering the upper atmosphere, these particles collide with atmospheric gases like oxygen and nitrogen. These collisions transfer energy, causing the gas atoms to become excited. When the atoms return to their baseline energy state, they release this excess energy as photons (light).
• Color Variations: The color of the aurora depends on the gas being struck and the altitude:
  • Green: Most common; caused by collisions with oxygen molecules at lower altitudes.
  • Red: Very rare; caused by high-altitude oxygen atoms (often observed during intense solar storms).
  • Blue/Purple: Caused by interactions with nitrogen.

E85 fuel 

In News: India launched E85 fuel—a blend of 85% ethanol and 15% petrol—on World Environment Day. Priced roughly ₹20 per litre cheaper than conventional petrol, this rollout by Public Sector Oil Marketing Companies aims to lower crude oil imports, support domestic farmers, and significantly reduce greenhouse gas emissions. 

Key Details of the E85 Launch

• Initial Availability: The fuel is currently available across 48 select retail outlets in major urban centers and regions like Delhi-NCR, Mumbai, Pune, and Nagpur. 
• Aggressive Expansion: The government plans to expand availability to 500 outlets by December 2026 and scale up to 5,000 outlets by December 2027.
• Vehicle Compatibility: E85 is not meant for regular petrol vehicles. It is strictly formulated for certified Flex-Fuel Vehicles (FFVs) designed to run on ethanol blends between E20 and E100. 
• Environmental Impact: Utilizing locally produced ethanol in high concentrations cuts lifecycle greenhouse gas emissions by up to 61% and heavily reduces particulate matter emissions. 

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