Diwali

On the left you can see the view of India from satellite in a regular night, in the right hand is India during Diwali, the Festival of lights, the most important event on the Hindu calendar, the festival marks the victory of good over evil and the start of the New Year. 

How you can read in this interesting article by Asia News, celebrations last five days but the third, which this year fell on November 13, is the most important because it is dedicated to Lakshmi, the goddess of prosperity and good fortune. On this day, families clean their homes and keep clay lamps or 'diyas' lit overnight to welcome the divinity. 

According to tradition, Diwali marks the return of Lord Ram to Ayodhya (Uttar Pradesh) after vanquishing the demon king Ravana and rescuing his wife Sita. Together, husband and wife enter the city welcomed by thousands of glowing lamps.

For Hindus, Rama represents the seventh manifestation (avatar) of the god Vishnu, and Sita is the incarnation of his wife Lakshmi. The prince's adventures are told in the Ramayana, one of Hinduism's most important poetic epics.