Makar Sankranthi, Lohri, and Pongal mark the movememt of the Sun from the Tropic of Cancer to the Tropic of Capricorn, or from the Dhanu rashi (Sagittarius) to Makara rashi (Capricorn) as it goes on its celestial path.
An intersting fact is that this festival marks the Winter Solstice i.e., the gradual increase in the length of the day. Scientifically, December 21-22 is the shortest day. So, Winter Solstice begins on this day, and the Sun enters the Makara rashi on this day. However, since the Earth tilts 23.45 degrees, it has caused Makar Sankranthi to shift. A thousand years ago, Makar Sankranthi was on December 31, now it is January 14. 5000 years on, it will be at the end of February, and after 9000 years it will fall in June!
Makar Sankranthi is a day when the Sun is worshiped. People celebrate this festival across India in many ways. It is also a day when a ritual bath for thepurification of sins is taken in the Ganges. In fact, in Bengal, the day is celebrated as Ganga Sagar when thousands take a dip in the holy Ganges at the auspicious pre-dawn hour. Kites are flown on this day as a tribute to the Sun God.
Lohri is celebrated in Punjab, Haryana, Himachal Pradesh, Delhi and Jammu. People associate Lohri with Dulla Bhatti, a Robin Hood-like rebel who robbed the rich and gave to the poor, and rescued Hindu girls from being sole into slavery arranging their marriages and giving them their dowries. The lyrics of all Lohri songs express gratitude to Dulla Bhatti. The main feature of Lohri is the big bonfire which is lit in the main square.
Thai Pongal is celebrated by Tamilians in India and Sri Lanka. The saying "Thai Pirandhal Vazhi Pirakkum" or "the commencement of Thai paves the way for new opportunities" is reflected in this festival. In gratitude to the Sun God for a good harvest, the first grain is consecrated to him. Tamilians decorate their homes with banana and mango leaves, both considered auspicious, and decorate their homes with exquisite kolams (rangolis) made with rice flour. Milk is boiled in a clay pot till it boils over, symboizing prosperity for the home. All South Indian states celebrate Pongal by different names.
As all festivals go, there is a lot of fun, singing, dancing of traditional dances, eating, and drinking.
So Happy Celebrations!! It's the mark of a New Season!!!