Hyderabad:The sun rising in the east is a universal truth that we all grew up believing. However, actual observations suggest otherwise. “As children, we are taught in schools that the sun rises in the east. But if you observe the sun every day, you will find that it does so only twice a year – during the March and September equinoxes,” said Raghunandan Kumar, founder of the Planetary Society of India. Director.
The Northern Hemisphere will experience the winter solstice on December 21 at 2.50 PM IST. Equinoxes and solstices, key astronomical events, are familiar concepts from school. An equinox occurs when the length of day and night are approximately equal, while a solstice marks the longest or shortest day of the year. Both events occur twice a year – the equinoxes in March and September and the solstices in June and December.
Explaining how the winter solstice is an important milestone in Earth’s journey around the sun, Raghunandan said, “Between December and March, the sun rises somewhere between northeast and east. On December 21, the winter solstice, it will rise to the northeast. Gradually, the sun moves eastward, and by March 21, the vernal equinox, it will rise due east.
Why does this happen? Raghunandan attributed this to the axial tilt of the earth. “Earth’s axis is an imaginary pole running from top to bottom through its center. The planet rotates around this axis, completing one turn each day, giving us day and night. The Earth’s rotation around the Sun is tilted at an angle of 23.5 degrees, causing the weather to change. ,’ he said.
Solstice occurs twice a year. For the Northern Hemisphere, the summer solstice occurs around June 21, and the winter solstice occurs around December 21. During the winter solstice, the Northern Hemisphere receives the least direct sunlight, resulting in cooler temperatures, while the Southern Hemisphere experiences more direct sunlight. sunlight This pattern reverses during the June solstice.
December 21 brings the shortest day and longest night of the year in the Northern Hemisphere. From this day, the days gradually get longer until June 21, which is the longest day and shortest night.
Ancient civilizations, without telescopes or satellites, observed the sun’s path, the length of daylight, and the shifting of the sunrise and sunset to predict the seasons—an important skill for survival. They also built monuments such as Stonehenge in England and Torren in Machu Picchu, Peru to track the sun’s progress.
“About 200 km from Hyderabad, in Mudumal village of Narayanpet, similar stone structures called ‘Niluvu Rallu’ (flying stones) were built by ancient people. These structures served as cosmic calendars, helping them predict seasonal changes based on the movement of the sun. The knowledge allowed them to grow crops. The events – the two solstices and the two equinoxes – were important for planning the agricultural cycle, which guided the determination of the correct timing of sowing and harvesting. was,” said Raghunandan.
Mudumal has 80 standing stones arranged in rows, each 5 meters apart. These stones probably helped measure time and identify the seasons.
Encouraging the younger generation to follow in the footsteps of their forefathers, he said, “Students should observe and document the sunrise and sunset once every week for 54 weeks. By collecting these images, they will see significant changes in the sun’s height, timing and direction. They will also observe its relationship with seasonal changes.
Raghunandan concluded, “It is important for children to understand how cosmic events affect our daily lives.